tag:blogger.com,1999:blog-36370619295243364352024-03-13T12:31:17.866+00:00Electric PenguinlandNot limited to: Linux, brain science, music, guitars, chess. But not necessarily including them either.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.comBlogger27125tag:blogger.com,1999:blog-3637061929524336435.post-86561044784259564262015-02-03T00:05:00.001+00:002022-03-22T16:02:34.402+00:00Peaceful tuning, Pacifica 112<br />
Hello again!<br />
<a href="http://2.bp.blogspot.com/-2yrDj2x9kqA/VM_wKEXmhrI/AAAAAAAABCQ/cXF68iTiPUM/s1600/DSCN9578_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="240" src="http://2.bp.blogspot.com/-2yrDj2x9kqA/VM_wKEXmhrI/AAAAAAAABCQ/cXF68iTiPUM/s1600/DSCN9578_s.JPG" width="320" /></a>It's been over a year since my <a href="http://epenguin.imalone.co.uk/2013/11/pure-drumming.html" target="_blank">last post (Pure Drumming)</a>. I started Electric Penguinland as a series of notes-to-self, to write up things that were difficult to discover online. I'm glad people have found the odd thing I've posted useful, so I'm picking up with the article that I was planning to start <i>last</i> year with: replacing the tuners on a Yamaha Pacifica.<br />
<br />
<a name='more'></a>This is my occasionally-modified Pacifica 112. The tuners it comes with are fine, but they were getting old and a bit worn, so there was travel on the knobs and the pegs themselves could wobble a bit. Actually replacing the tuners (or machine-heads) is not terribly difficult, the trick is finding out what to replace them with. Along the way we'll go over some of the different options. If the following seems like a shaggy dog story at least it might save someone from going up the same garden path.<br />
<h3>
Original tuners</h3>
This is a pre-112V model (maybe 2007?), with 6-a-side modern tuners. The 6-a-side simply means all 6 are on the same side of the headstock, unlike a Gibson or many acoustic guitars with have 3 tuners on either side. All 6-a-side tuners in a set will be the same, in 3-a-side set three of them will be left-handed and the other three right handed (the tuning key coming out of one side or the other). "Modern tuners" are a compact cylindrical shape with a flat side for the tuning key. This is sometimes called Gotoh style after the Japanese company who popularised them (and confusingly make lots of other types). The other major type are square and sometimes called traditional or vintage (or Grover, again a company who make lots of types).<br />
The other thing to notice is there's no obvious screw holding them in. What is? It turns out there are two small guide pins under the straight side. Trying to make sure I got ones that would fit this is what caused most of the headaches. A year on I think if I did this I might just drill the holes for screws, but that's not what happened. More on this later...<br />
<h3>
More precisely</h3>
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These pictures show one of the original tuners being measured up. The tuner holes are a standard 10mm. The distance between the pins (10mm) and from the pins to the tuner peg centre (a bit less than 10mm) turn out to be typical for this pattern of tuners.<br />
<b>(Except</b> Fender American standard tuners, which have a longer distance between the guide pins and the tuning peg. These are also more rectangular when looked at from behind.)<br />
Chinese companies like JinHo and Metallor make this pattern. Getting hold of them is not very hard, but often stock photographs don't show whether or not there is a tab or pins which makes things tricky (the answer is usually tab). Part numbers tend to be WJ805, WJ807, J802, J805 and J807 seem to be common for guide-pins. If you see one of those without the 8, for example, WJN-03, it's probably <i>not</i> the pin version.<br />
<h3>
The golden ratio</h3>
One thing to consider is tuner ratio, which is where I got a bit stuck. Most cheap tuners are 15:1, meaning you turn the knob 15 times for every turn of the peg. The higher that number is the more precise control you have. Those WJ part numbers are Wilkinson locking tuners. These can come in 19:1 ratios, which I was keen to use, and so spent a while trying to hunt them down in this guide-pin form.<br />
In short it doesn't exist, Wilkinson (or at least their UK distributors, JHS) seem to have discontinued the guide pin model. I managed to get hold of a set of the remaining ones. The normal (screw-tab) EZ-lok are now all 19:1, but the guide pin versions when they arrived were 15:1. So if you're determined to stick with guide pin versions (to avoiding drilling any holes is really the only reason), it'll have to be a 15:1 set. In the UK Northwest Guitars do a <a href="http://www.northwestguitars.co.uk/button-shpaed-machine-heads/" target="_blank">set</a>, and Guitars and Woods sell a Wilkinson <a href="http://guitarsandwoods.com/accessories/Machine-heads-tuners/wilkinson-wj807-chrome" target="_blank">non-locking</a> model which is probably 15:1. 15:1 is fine, you can easily tune a guitar with 15:1.<br />
<h3>
Changing tune </h3>
Actually changing the machine heads is simple. Get a spanner, unscrew the nut on the front side of the headstock and then pull the tuner out the back. Then just put the new tuners in (lining up those troublesome pins) and screw in the new sleeve, tighten with spanner. Done.<br />
The alternative is to accept you're going to have to drill screw holes, this opens up the option of any tuner with a screw tab. They're not all in the same place—high end tuners like Grovers and Hipshot notably put the tab in a slightly odd position—but most are 45 degree and at least you have a choice. You could get the Wilkinson EZ-lok (in reality the design doesn't 'lok' very well, but it does let you use staggered heights), but these days I prefer wheel locking tuners, there are inexpensive ones from <a href="http://www.axetec.co.uk/guitar_parts_uk_037.htm#e90" target="_blank">Axetec</a> and <a href="http://www.axesrus.co.uk/Axesrus-Rear-Disc-Locking-Machine-Heads-p/jn-07.htm" target="_blank">Axesrus</a> among others. And happily those come in 19:1.<br />
However, for the moment the Wilkinsons are staying on.<br />
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Anyone wondering if there's something odd about this last picture is right. It was so tricky to get these that I had to buy button ones. I tried putting the old knobs on (so, one hex knob in the picture), but in the end decided I actually like the buttons. So one good thing has come out of this!justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com2tag:blogger.com,1999:blog-3637061929524336435.post-69023624059453813082015-01-28T01:18:00.003+00:002022-03-22T16:02:41.956+00:002015<div class="separator" style="clear: both; text-align: center;">
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<h2>
<span style="font-size: large;"> Electric Penguinland Will Return...</span></h2>
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<br />justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-67318266287179141602013-11-07T01:02:00.000+00:002022-03-22T16:02:49.148+00:00Pure drumming<a href="http://4.bp.blogspot.com/-nCHO47fD3d0/UnrjkD2JioI/AAAAAAAAAhs/B2g1r-B9QDs/s1600/drumbox.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="220" src="http://4.bp.blogspot.com/-nCHO47fD3d0/UnrjkD2JioI/AAAAAAAAAhs/B2g1r-B9QDs/s1600/drumbox.jpg" width="320" /></a>All too often I find ways to distract myself when I've intended to do some guitar practice. Recently I thought it would be nice to create some drum tracks to play with. "No problem!" You say, "Use <a href="http://www.hydrogen-music.org/">Hydrogen</a>." This is a start, but what if you don't know much about drumming and find clicking beats on a track comes out a bit flat? The first thing to come to mind was to try some <a href="http://en.wikipedia.org/wiki/Midi" target="_blank">MIDI</a> pads, but that seemed like overkill, especially when something with buttons on it was much closer to hand—my Xbox 360 controller.<br />
<br />
<a name='more'></a>There are drawbacks to doing this. For one thing proper MIDI pads or keyboards can sense velocity (how hard you hit the keys) which can be used to control volume for example. And the ideal layout for battling alien invasions isn't necessarily the one you'd want to write the next <a href="http://en.wikipedia.org/wiki/Four_Sticks" target="_blank">Four Sticks</a>. But if you've got some kind of gamepad lying about that you want to transform into a miniature drum kit then it's certainly possible.<br />
The trick is that most synths, including drumkits like Hydrogen, talk MIDI. Since it stands for "Musical Instrument Digital Interface" you can probably guess that most gamepads do not. Gamepads usually use a protocol called <a href="http://en.wikipedia.org/wiki/USB_human_interface_device_class">USB-HID</a> "Human Interface Device". But since these are all just 0s and 1s shuffling around your computer we should be able to find something that can redirect them from one to the other.
The something I used is called <a href="http://puredata.info/" target="_blank">Pure Data</a>.<br />
Pure Data is a "data flow programming language", in simple terms you draw lines between things you want to connect. Once you've got a "patch" (graph) you like that's the program and you just run it.<br />
Pure Data isn't part of normal Fedora, but you can get it easily by following the instructions at <a href="http://ccrma.stanford.edu/planetccrma/software/" target="_blank">Planet CCRMA</a> (pronounced 'karma'). Just follow the "Adding the planet CCRMA repositories." instructions, then do<br />
<pre>yum install pd-extended</pre>
to get Pure Data, this is actually one of their examples. (CCRMA is the Stanford University Centre for Computer Research in Music and Acoustics.)<br />
Then it's just "pd" to run it, or start it from the menu.<br />
<br />
<h3>
Getting graphic</h3>
It's possible to just load the patch and run it, but read on if you want to know what it's doing or how to adjust it.<br />
Things aren't quite as simple as joining a 'X-Box' box to a 'Hydrogen' box, mainly because we need to say what we want the buttons to do. This is the whole patch:<br />
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<a href="http://2.bp.blogspot.com/-uJWBeeWLXZM/UnrICfE4i0I/AAAAAAAAAg8/v5rLGm2tc3g/s1600/finalgraph.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="http://2.bp.blogspot.com/-uJWBeeWLXZM/UnrICfE4i0I/AAAAAAAAAg8/v5rLGm2tc3g/s1600/finalgraph.png" width="311" /></a></div>
And this is the first bit that connects to the 360 controller (or any USB HID controller). The "HID" part is the magic box that receives gamepad instructions, the rest of the controls are to set it up: with the patch running you can click "print" to get info on the available controllers, then use the radio control to select the controller you want (mine is number 4) and the checkbox on the left to start reading. (The radio control here isn't a plain control, it's a copy of the one from the HID help information.)<br />
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<a href="http://3.bp.blogspot.com/-IUY1xZfY_l8/UnrOl2HcE3I/AAAAAAAAAhY/cO9t2mrVfck/s1600/gethid.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="104" src="http://3.bp.blogspot.com/-IUY1xZfY_l8/UnrOl2HcE3I/AAAAAAAAAhY/cO9t2mrVfck/s1600/gethid.png" width="320" /></a></div>
...and this is the end:<br />
"makenote" generates midi notes and "noteout" sends them into the world. The two numbers are "velocity" (100 out of 127) and duration (10ms, which Hydrogen will ignore).<br />
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<a href="http://1.bp.blogspot.com/-57WzpT6EzjY/UnrOl0cMsnI/AAAAAAAAAhM/w6PNWKz5IYE/s1600/make-note.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://1.bp.blogspot.com/-57WzpT6EzjY/UnrOl0cMsnI/AAAAAAAAAhM/w6PNWKz5IYE/s1600/make-note.png" /></a></div>
What 'note' is played goes in at the left hand side. The 'print' writes text to the PD console whenever a note plays. Hydrogen will interpret this as which sample to play, which is where the nest in the middle comes in:<br />
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<a href="http://3.bp.blogspot.com/-0T_w_y-cA3E/UnrOl4ZELLI/AAAAAAAAAhQ/XwXpheOZeHA/s1600/map-keys.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/-0T_w_y-cA3E/UnrOl4ZELLI/AAAAAAAAAhQ/XwXpheOZeHA/s1600/map-keys.png" width="309" /></a></div>
'route key' sorts out the key presses that arrive from the controller from other events (like joysticks). Which 'btn_' is which can be found by clicking the top left print with the controller running: each 'route btn_X' is picking up a particular button and the 'sel 1' means it only triggers on pressing, not when releasing. The numbers on the right are notes. <a href="http://www.hydrogen-music.org/hcms/node/5#sect.pattern_editor.drumkit" target="_blank">Each one maps to a slot in the Hydrogen dumkit</a> starting at 36 for the first slot (the kick drum in the normal kit). With the default kit this means:<br />
<ul>
<li>A - Tom low</li>
<li>B - Snare Jazz</li>
<li>X - Closed HH</li>
<li>Y - Snare rock</li>
<li>Left shoulder - Crash</li>
<li>Top right - Stick</li>
<li>Back - Tom Mid</li>
<li>Start - Pedal HH</li>
<li>Big-X - Kick</li>
</ul>
If you want to know more about <a href="http://puredata.info/" target="_blank">Pure Data</a> you can check out the website for
more information and mailing lists, but one of the most useful help
sources is hidden in plain sight. If you right click any object (box) you
get a menu, click help and a new patch window will open demonstrating all the things you can do with that object. The HID help window is where I found the augmented radio control needed to make an input selector.<br />
<ul>
</ul>
<h3>
Bash it out </h3>
Download <a href="https://sites.google.com/site/ibmalone/pd-xbox-hydrogen-kitsetup.pd" target="_blank">the patch</a>. <br />
Load PD and Hydrogen (and Jack if you're using it). Since Hydrogen uses the ALSA MIDI system set the PD output to ALSA too (the "Media" menu). If you're using QJackCtl to manage Jack you can also look at the ALSA MIDI tab to check PD and Hydrogen have connected.<br />
Then just load the patch in PD and set it running by toggling edit mode (Ctrl-e, or menu, Edit|Edit mode). Click the top left print to check which input number you need, use the radio box to select it and then click the checkbox if it's empty.<br />
Things not working?<br />
<ul>
<li>Check note numbers are coming up in the PD console when you press buttons (that's the text window that launches when you run PD). If not you might have a problem with the HID input, look carefully at the 'print' information again.</li>
<li>If note numbers are coming up, check Hydrogen is working by clicking on a drum name in the main window, that should play a sample. If it doesn't then Hydrogen isn't able to play sound properly. If it does there might be a MIDI connection problem, check the MIDI-in light at the top of the Hydrogen window flashes when you press a button. If it doesn't then MIDI signals aren't being received.</li>
</ul>
<h3>
Beat a drum?</h3>
This certainly works and is quite fun to play with. If nothing else it was a good way to find out whether it's worth going ahead and getting some proper MIDI controllers for this.<br />
For those on Windows or Mac, PD-extended and Hydrogen are both available for these, so you should be able to get this working there too. <br />
<br />
<ul>
</ul>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-10135579209260925092013-10-11T00:37:00.002+01:002022-03-22T16:03:05.855+00:00MathJax postsMy posts on the <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-1-maths-rock.html" target="_blank">string bend calculator</a> used <a href="http://www.mathjax.org/" target="_blank">MathJax</a> to display the equations used. But I ended up struggling a while to get them to work on mobile devices. The problem is this: typically MathJax loading needs to go into the document head, but that means editing your blog template.<br />
<br />
<a name='more'></a>There are three problems with loading MathJax in your blog template. Firstly it will get loaded for every page, even those that don't need it. Secondly changes to Blogger can apparently break it, requiring work-arounds. Thirdly, to get it to work on mobile devices you have to use a custom template shared with your normal site. Correctly tweaking the template to work on both desktop and mobile would have been hard work. At the same time, having to load MathJax for every page would be even more of a burden for mobile devices.<br />
The apparently simple solution is to put MathJax in the post body instead. This snippet shows how I've put it in the HTML editor in the posts that needed it:<br />
<!--HTML generated using hilite.me--><br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;"><span style="color: #888888;"><!--more--></span><span style="color: #007700;"><script </span><span style="color: #0000cc;">type=</span><span style="background-color: #fff0f0;">'text/x-mathjax-config'</span><span style="color: #007700;">></span>
MathJax.Hub.Config({tex2jax<span style="color: #333333;">:</span> {inlineMath<span style="color: #333333;">:</span> [[<span style="background-color: #fff0f0;">'$'</span>,<span style="background-color: #fff0f0;">'$'</span>], [<span style="background-color: #fff0f0;">'\\('</span>,<span style="background-color: #fff0f0;">'\\)'</span>]], displayMath<span style="color: #333333;">:</span> [[<span style="background-color: #fff0f0;">'\\['</span>,<span style="background-color: #fff0f0;">'\\]'</span>]], processEscapes<span style="color: #333333;">:</span> <span style="color: #008800; font-weight: bold;">true</span>}});
<span style="color: #007700;"></script></span>
<span style="color: #007700;"><script </span><span style="color: #0000cc;">src=</span><span style="background-color: #fff0f0;">'https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG'</span><span style="color: #007700;">></script></span>
<span style="color: #007700;"><script </span><span style="color: #0000cc;">src=</span><span style="background-color: #fff0f0;">'http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG'</span><span style="color: #007700;">></script></span>
</pre>
</div>
The <script> elements go after the jump-break (the <!--more--> comment), this means they don't load on the front page. If you did use maths in the leader you could put them there to ensure it worked properly whenever the leader was in view. Unlike script elements in <head> these can't be empty, so need a </script> closing tag.<br />
<br />
There are two script elements, one for http and one for https, this is because the MathJax CDN has different addresses for http and https and because Firefox security can prevent mixing secure and insecure elements in a page. Normally with CDNs you can use 'relative protocol' (basically leave out the 'http:' or 'https:'), but this doesn't work when the addresses are different. With both sources given separately it will work whether http or https is used.<br />
<br />
The TeX-AMS-MML_SVG renderer is used because I was unhappy with the way bracketed fractions were displayed in the default renderer so went for SVG instead.<br />
<br />
Finally the "text/x-mathjax-config" section, thanks to <span class="gD" name="Peter Krautzberger">Peter Krautzberger on the <a href="https://groups.google.com/forum/#!forum/mathjax-users" target="_blank">mathjax-users list</a> for help with this. I previously had </span>a configuration that used entity references (&#39; instead of ') to work within a Blogger template, this doesn't work in the post body. Instead you just need the plain JavaScript, the same as you'd use anywhere else. I've actually dropped the custom configuration altogether now, as I was only using it to allow $x=y$ type notation.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-1790237895363444752013-10-11T00:32:00.003+01:002022-03-22T16:04:37.002+00:00Making the pitch - tuning<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://upload.wikimedia.org/wikipedia/commons/thumb/d/de/PitchPipes.JPG/594px-PitchPipes.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" height="258" src="https://upload.wikimedia.org/wikipedia/commons/thumb/d/de/PitchPipes.JPG/594px-PitchPipes.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Guitar pitch pipes, <a href="https://commons.wikimedia.org/wiki/File:PitchPipes.JPG" target="_blank">Wikimedia</a></td></tr>
</tbody></table>
If you play guitar then you need to tune it from time to time, unless you're deeply in to experimental music.<br />
<br />
<a name='more'></a><br />
It's possible to tune by ear using tuning forks or pitch pipes. Tuning by ear is a useful skill and it's what orchestral players often do (because some instruments like pianos cannot be retuned easily, so you have to tune to match them). But it takes lots of practice to do efficiently.<br />
<h3>
Heads up</h3>
The cheapest practical alternative are electronic headstock tuners. These are all broadly similar, but performance can
vary. I have a Snark SN-8 'super tight' which is better
than previous ones I've tried (guitarman, guitartech), achieving a faster and more stable lock onto the note. When using a headstock tuner try to put it where
vibration on the headstock is strongest.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-_IfZxLaroYk/Ulcr0OiEsnI/AAAAAAAAAfk/UD3ilrsmBpM/s1600/DSCN9033_s.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://2.bp.blogspot.com/-_IfZxLaroYk/Ulcr0OiEsnI/AAAAAAAAAfk/UD3ilrsmBpM/s1600/DSCN9033_s.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Snark SN-8 on left and Guitarman on right</td></tr>
</tbody></table>
Snarks now seem to be about
the same price as the previously cheaper alternatives now and most also have a metronome, of the ones I've tried they're definitely my favourite. Recently some very small ones have also appeared, like the Planet Waves tuner, if small and discrete is better for you.<br />
<h3>
On your bike </h3>
The next type of tuner is a pedal tuner: these use the same electronics to analyse the signal, but instead of using a piezo-pickup to detect the note on the headstock they plug into your guitar's signal chain (obviously you need an electric or electroacoustic to use these).<br />
There are advantages and disadvantages to pedal tuners. They are a bit more expensive and not as easy to carry around as headstock tuners, and if you're using a plain acoustic guitar then you have no way to plug it in.<br />
But pedal tuners really shine on stage. Since they read the guitar signal they will still work even in the presence of background noise (headstock tuners might be confused by loud background). They will also often allow you to mute while tuning and can be there all the time while not threatening to fly off at the wrong moment.<br />
Recent pedal tuners like polytunes also offer the
ability to tune multiple strings at once, so you just strum and it tries
to lock and show all six notes.<br />
<h3>
Strobe </h3>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-FL6oyHyreiY/Ulcy1WjWpnI/AAAAAAAAAf0/KlRj1lLYF-w/s1600/lingot.png" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="http://3.bp.blogspot.com/-FL6oyHyreiY/Ulcy1WjWpnI/AAAAAAAAAf0/KlRj1lLYF-w/s1600/lingot.png" /></a></div>
Stroboscopic tuners are more accurate than either headstock or normal
pedal tuners and also more expensive. These work on the principle that repeating the guitar signal at the frequency you're tuning to should produce a steady pattern (this is similar to tuning two notes together by listening to beats). There are also 'digital
stroboscopic tuners' which are a bit cheaper. The best known maker, Peterson, even does a headstock version. These might not be needed for everyday use, but some people like them for the ability to
do sweetened tunings and things like guitar setups (intonation) and studio work can need the
accuracy. On the other hand you may well despair when you find out it's actually impossible to get that note to stay absolutely still.<br />
These days a good tuner program for your computer can get as good accuracy provided you have a way to plug
your instrument in. I like Lingot <a class="postlink" href="http://freecode.com/projects/lingot" rel="nofollow" target="_blank">http://freecode.com/projects/lingot</a>, which also has a Windows version, <a class="postlink" href="http://lingot.gitara.org.pl/index.php.en" rel="nofollow" target="_blank">http://lingot.gitara.org.pl/index.php.en</a>. Under Linux Lingot can read from Jack or ALSA (and therefore also Pulseaudio), so whatever setup you're using it will probably work. It also supports <a href="http://www.huygens-fokker.org/scala/downloads.html#scales" target="_blank">Scala files</a> so there is a large set of altered (non-TET12) tunings available and being able to display the spectrum lets you see how well the notes are being detected.<br />
<h3>
We'll call you</h3>
The last option are hand-held tuners. Until recently headstock tuners had nearly killed these. A hand-held tuner has a microphone, so is less able to pick up the instrument signal, but it's also able to work with non-stringed instruments. (Should you want to tune your saxphone. Actually, can you tune saxophones?). The common experience is trying to play the note while waving the tuner in front of the strings hoping it will detect it. But recently they've made a comeback, because a smartphone can work as one. I've got a free app for Android called <a href="https://play.google.com/store/apps/details?id=com.symbolic.pitchlab" target="_blank">PitchLab</a>. While they still have the drawbacks of old handheld tuners (I'm sticking with my Snark), phone microphones are maybe a bit better and they can also do some clever things: the PitchLab tuner has a strobe mode (which does work on the strobe principle) and a chord detector.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-62151158204679544872013-08-24T03:09:00.006+01:002022-03-22T16:05:31.435+00:00Bending with Dojo part 1: Maths rockOne of the distinctive sounds of the guitar is bending notes, pushing or pulling the string sideways across the fretboard to raise its pitch. Santana's Samba Pa Ti and Pink Floyd's Shine On You Crazy Diamond have classic examples, but whether you're listening to BB King or Noel Gallagher it'll show up from time to time.<br />
But guitar strings are steel, they can't stretch that much can they? Some people have trouble believing this and think there must be 'give' somewhere else, but a guitar string is thin and long and really can stretch, so I thought I'd put together a <a href="http://www.imalone.co.uk/stringbendcalc.html" target="_blank">string bend calculator</a> to show how. Using it should be self explanatory, this series of posts is about what's happening under the hood.<br />
<br />
<a name='more'></a>
<script src="https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG"></script>
<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG"></script>
The following is roughly divided up into a chunk of maths, some web programming (<a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-2-stretching-in.html">part 2</a>), complications and fun and games with equations (<a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-3-slight-return.html">part 3</a>).<br />
<h3>
Shakin'</h3>
Guitar strings make a note by vibrating at a particular frequency, they do this because they're under tension. When you pluck a string the tension tries to pull it straight again, but because the string is quite free to move it overshoots, it keeps overshooting and getting pulled back, gradually losing energy (and getting quieter). The more tension the faster the cycle goes (higher pitch), the heavier the strings are the slower it goes.<br />
You can write this down as an equation for the speed of a wave travelling down a string under tension:<br />
Speed of vibration along string \(c = \sqrt {\frac{T}{\rho}}\), you can probably guess \(T\) is tension, \(\rho\) is the "linear density" e.g how much a metre of string weighs (or how massive it is for the pedants out there). The different types of density get important a bit later.<br />
The observant reader will be saying waves don't travel down a guitar string (where would they go?), it vibrates side to side. This is true, one way of looking at it is they get reflected at each end, called a standing wave. However we can still use the same relations for speed (c), frequency (f) and wavelength (w). (If you're following along with a physics textbook you might have \(\nu\) for frequency and \(\lambda\) for wavelength, but let's try and keep it simple here. Also I'm saving l for later.).<br />
Quite simply, \(\mbox{speed}=\mbox{frequency}\ times\ \mbox{wavelength}\), or \(c=fw\).<br />
Since we don't care about the speed along the string (or maybe you do, I don't right now), we get rid of it:<br />
\[fw= \sqrt{\left( \frac{T}{\rho} \right)} \]<br />
<br />
<h3>
How long is a piece of string?</h3>
The wavelength (w) above is the distance between the start and stop of the "S" that makes up a wave, but the standing wave on a guitar string doesn't look like this. It's one half of it (the second harmonic does look like an S, but we're interested in the string notes here). So if the length of the string (l), between the bridge and the nut (the "scale length") is half the wavelength, then \(w=2l\).<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-zG6zeJlJNTo/UgXp41cY8eI/AAAAAAAAAdU/imZRm_Emfkg/s1600/guitarsketch-harmonics.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://2.bp.blogspot.com/-zG6zeJlJNTo/UgXp41cY8eI/AAAAAAAAAdU/imZRm_Emfkg/s1600/guitarsketch-harmonics.png" /></a></div>
<br />
<h3>
Getting tense</h3>
Since we want to know about string stretching and that will depend on tension, we want to rewrite things with the tension dependent on the other factors:<br />
\[(2fl) = \sqrt{\frac{T}{\rho}} \\<br />
(2fl)^2 = \frac{T}{\rho} \\<br />
4f^{2}l^{2}\rho = T \]<br />
<h3>
Row your boat</h3>
(For the non-Greek speakers out there, \(\rho\) is pronounced "row"...) We've said that's the density as mass-per-length of the string, but if you look up the density of steel you'll find the mass-per-volume (call it \(d\)), kilogrammes per cubic meter (\(kg\ m^{-3}\) or the Imperial equivalent, grains per cubic chain or whatever). This is because strings come in different thicknesses. To get from \(d\) to \(\rho\) we multiply by the cross sectional area of the string, which is a circle.<br />
\[\rho=d\pi r^2 = d \pi \left(\frac{g}{2}\right)^2 = \frac{dg^2\pi}{4}\]<br />
\(\pi r^2\) is the usual way to write the area of the circle, but the radius \(r\) is just half the width of the diameter or gauge \(g\).<br />
\[T=(flg)^{2}\pi d\]<br />
<h3>
Stretch it</h3>
If you remember school physics lessons then you probably remember Hooke's Law. This says the displacement (stretch) of a spring is proportional to the force stretching it. A similar rule works for some solid materials like steel, where the stress (\(\sigma\) tension over an area) is proportional to the strain (\(\epsilon\) stretch relative to original length). The relation is given by the Young's Modulus, \(E\).<br />
\[ \sigma = \epsilon E \\<br />
\frac{T}{A}=\frac{T}{\frac{1}{4}\pi g^2}=E\frac{s}{L}<br />
\]<br />
\(s\) is the distance the string stretches by, \(L\) is the full length of the string. We already used small \(l\) for the scale length, but on most guitars the part of the string between the headstock and the tuners is also under tension.<br />
<h3>
Getting toned</h3>
Musicians don't deal in frequencies, they use notes. We need to be able to convert from notes to frequencies. It's fairly well known that for every octave you go up the frequency of the note doubles. If you know a bit more about equal temperament tunings then you'll know that for each semitone the frequency multiplies by \(2^{1/12}\). So if we know what frequency one note is then we can work out any other note by knowing how many octaves and semitones up or down it is.<br />
The standard most often used is "A440", where the A above middle C is at 440Hz. So what frequency is the low E guitar string? We need to know the octave. Something called <a href="http://en.wikipedia.org/wiki/Scientific_pitch_notation" target="_blank">scientific pitch notation</a> is useful here, this gives each octave a number, middle C is the 4th octave, or C<sub>4</sub>. A bit confusingly each octave starts at C, so the 440Hz A is A<sub>4</sub>. So in the 4th octave we need to count semitones down from A<sub>4</sub> to C<sub>4</sub> and up from A<sub>4</sub> to B<sub>4</sub>.<br />
\[f=2^{(\mbox{oct}-4)+\mbox{st}/12} * 440Hz \]<br />
Where "oct" is the octave and "st" is semitones above or below (negative) A. The low E string is E<sub>2</sub> or about 82Hz.<br />
<h3>
The final stretch</h3>
So how much does a string stretch with a bend of \(n\) semitones? To get the bend you pull the string, raising the tension by enough to get the pitch. Call this higher tension \(T_2\), the new note \(f_2\).<br />
\[T_{2}=(f_{2}lg)^{2}\pi d \\<br />
\frac{T_2}{T} = \frac{(f_{2}lg)^{2}\pi d}{(flg)^{2}\pi d} = \left(\frac{f_2}{f}\right)^2\]<br />
And we can write the ratio of \(f_2\) and \(f\) in terms of \(n\) semitones<br />
\[T_2=T(2^{n/12})^2=2^{n/6}*T \\<br />
T_2 - T = (2^{n/6}-1)T \]<br />
Why \(T_2 - T\)? The string is already under tension, what we want to know is how much more tension is needed. The extra stretch is then found by using that in the Young's modulus equation:<br />
\[ s=\frac{L}{E}\frac{(2^{n/6}-1)T}{\frac{1}{4}\pi g^2} \]<br />
We could start substituting more things in here, but it's useful later to be able to do things with the tension, so we'll stop there.<br />
<br />
Mathematical symbols in this post handled by <a href="http://www.mathjax.org/" target="_blank">MathJax http://www.mathjax.org/</a> using as in <a href="http://epenguin.imalone.co.uk/2013/10/mathjax-posts.html" target="_blank">this post</a>.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-75975033715245491612013-08-24T03:09:00.005+01:002022-03-22T16:05:19.503+00:00Bending with Dojo part 2: Stretching in the DojoFollowing on from <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-1-maths-rock.html">Part 1</a>, I wanted to make an interactive way to explore the mechanics of string bending. A spreadsheet is the simplest way to do that, but it needs users
to download a file and open it up with the right program. A web-app
only needs a browser and internet access to use, but takes a bit more
assembly. To cut down the amount of DIY needed it's common to use a <a href="http://en.wikipedia.org/wiki/Comparison_of_JavaScript_frameworks" target="_blank">framework</a>. <a href="http://jquery.com/" target="_blank">JQuery</a> is probably the most commonly used, but without built-in support for plots, so I went for the slight more complex <a href="http://dojotoolkit.org/" target="_blank">Dojo</a>.<br />
I
tried to make the maths background in Part 1 understandable for a general
audience, but this Dojo section is going to have to assume you know a
few programming terms. If that doesn't sound like your thing, then maybe you're just looking for the <a href="http://www.imalone.co.uk/stringbendcalc.html." target="_blank">string bend calculator</a>.<br />
<br />
<a name='more'></a><br />
<h3>
Lying</h3>
Not being a frequent Javascript user and using Dojo for the
first time I of course prototyped this as a completely procedural
program and then started to refactor it into a better design. I'm going
to pretend the final version is how it was meant to be all along.
However there are some beginner Javascript mistakes (or Dojo
peculiarities) I made along the way and they're included. They're useful
for me if no-one else.<br />
<h3>
Aiiieeee (IE)</h3>
I'm not anti-Microsoft, but they don't make it
easy. This one had me tearing hair out and tidying HTML and Javascript
until I found out it that using Dojo from a CDN (content delivery
network) just <a href="https://bugs.dojotoolkit.org/ticket/17146" target="_blank">doesn't work with Dojo 1.9</a>. Finding out that loading Dojo was the problem wasn't made any easier by IE 9
not reporting the failed load in web designer mode, IE 10 does tell you
about the problem. Changing to Dojo 1.9.1 fixed that.<br />
<h3>
What's that in old money?</h3>
Guitar related measures (scale, string
gauge) are often given in imperial units, so scale is 24.5 inches rather
than 648mm and string gauges are given in thousandths of an inch.
Metric on the other hand is much simpler for conversions and
calculations. So I wanted to have two controls for each of these that
would allow you to adjust in either system and update both boxes.<br />
This
turns out to be tricky, you set each control to update the other when
updated. Now when you update the metric control it updates the imperial
control, which wants to update the metric control again, which... etc.
While the cycle does stop it leads to weird effects like not being able
to set certain metric lengths. Dojo should let you pass a parameter to
stop this propagation, but it doesn't work in this situation. The
simplest solution is that each box checks whether the other box has
focus first and doesn't try to update it if it does.<br />
Incidentally, an inch is now defined to be exactly 25.4mm, so perfect conversion is possible.<br />
<h3>
Listing nothing</h3>
I've made use of some dropdown boxes to provide
suggested values for things like density and scale. These are filled
from lists provided in the code, mainly of "value" and "name" pairs.
Dojo handles null, 0 and null string values the same, which means that
even if you need a list of numbers it's best to supply the values as
strings, particularly to avoid problems with 0 being interpreted as a
default value ("0" instead is okay). That grates a bit on someone more
used to strongly type languages, but it's necessary with Javascript.<br />
Picking lint<br />
The code got quite a few passes through the useful <a href="http://www.jslint.com/" target="_blank">JSLint</a>,
particularly while trying to fix the IE problem above. Some things that
are Javascript idioms which you don't do in other C-like languages
became apparent:<br />
<ul>
<li>Variables in a scope get declared with a single 'var' statement,
separating multiple declarations and assignments with a "," rather than
making multiple ";" ended statements. This includes defining function
names.</li>
<li>Being statements, anonymous function declarations should have a ";"
after the braces (unless the assignment is in a list as above, where a
"," might be used).</li>
<li>Generally linting javascript is very useful since you don't have the same quality of compiler or interpreter warnings available.</li>
</ul>
<h3>
Ready: get, set, call</h3>
Because there are a lot of variables in the
model for string bending that need to be exposed to the interface and
update each other in complex ways a lot of getters and setters and
callbacks are needed. Writing them all is hard to maintain and makes the
JS bulky, there may be other ways to do this, but the solution I came
up with is to place this in the class constructor for the guitar string
after a list of "this.property=" assignments:<br />
<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;"> <span style="color: #008800; font-weight: bold;">var</span> nullfn <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span>(){},
ii, key,
updProps <span style="color: #333333;">=</span> [ {id<span style="color: #333333;">:</span> <span style="background-color: #fff0f0;">"bendstretch"</span>, tgt<span style="color: #333333;">:</span> <span style="background-color: #fff0f0;">"bendlat"</span>},
{id<span style="color: #333333;">:</span> <span style="background-color: #fff0f0;">"bendlat"</span>, tgt<span style="color: #333333;">:</span> <span style="background-color: #fff0f0;">"bendlatf"</span>},
{id<span style="color: #333333;">:</span> <span style="background-color: #fff0f0;">"bendlatf"</span>, tgt<span style="color: #333333;">:</span> <span style="color: #008800; font-weight: bold;">null</span>} ];
<span style="color: #008800; font-weight: bold;">this</span>.buildSet <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> (key) {
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"set_"</span><span style="color: #333333;">+</span>key] <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> ( newval ) {
<span style="color: #008800; font-weight: bold;">this</span>[key]<span style="color: #333333;">=</span> newval;
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"updated_"</span> <span style="color: #333333;">+</span> key]();
};
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"cb_updated_"</span><span style="color: #333333;">+</span>key] <span style="color: #333333;">=</span> nullfn;
};
<span style="color: #008800; font-weight: bold;">this</span>.buildUpdRecalc <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> (id, tgt) {
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"updated_"</span><span style="color: #333333;">+</span>id] <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> () {
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"recalc_"</span><span style="color: #333333;">+</span>tgt]();
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"cb_updated_"</span><span style="color: #333333;">+</span>id]();
};
};
<span style="color: #008800; font-weight: bold;">this</span>.buildUpdOnly <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> (id) {
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"updated_"</span><span style="color: #333333;">+</span>id] <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> () {
<span style="color: #008800; font-weight: bold;">this</span>[<span style="background-color: #fff0f0;">"cb_updated_"</span><span style="color: #333333;">+</span>id]();
};
};
<span style="color: #008800; font-weight: bold;">for</span> (ii<span style="color: #333333;">=</span><span style="color: #0000dd; font-weight: bold;">0</span>; ii <span style="color: #333333;"><</span> updProps.length; ii<span style="color: #333333;">++</span> ) {
key <span style="color: #333333;">=</span> updProps[ii];
<span style="color: #008800; font-weight: bold;">this</span>.buildSet(key.id);
<span style="color: #008800; font-weight: bold;">if</span> (key.tgt) {
<span style="color: #008800; font-weight: bold;">this</span>.buildUpdRecalc(key.id, key.tgt);
} <span style="color: #008800; font-weight: bold;">else</span> {
<span style="color: #008800; font-weight: bold;">this</span>.buildUpdOnly(key.id);
}
}
</pre>
</div>
(Formatting courtesy of <a href="http://hilite.me/">hilite.me</a>)<br />
Only
a few of the properties are shown, but each one simply defines the next
property that should be updated. The loop at the end creates a setter
and a null callback for each property. When set a property calls a
recalculate function for the next property in the chain (if there is
one) and the callback function which can be set by the interface. The
buildSet, buildUpdRecalc and buildUpdOnly methods are used to add these
functions to the class, using the "this[name]" method to address the
class properties (variables or methods) by name. Since they're methods,
"this" refers to the object being constructed, rather than a separate
function scope.<br />
Of course all the "recalc_property" methods still
need to be written, and will use the corresponding "set_property" method
to do the update, e.g.<br />
<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;"> recalc_bendforce <span style="color: #333333;">:</span> <span style="color: #008800; font-weight: bold;">function</span> () {
<span style="color: #008800; font-weight: bold;">this</span>.set_bendforce(
<span style="color: #008800; font-weight: bold;">this</span>.calcbendforce ( <span style="color: #008800; font-weight: bold;">this</span>.tension, <span style="color: #008800; font-weight: bold;">this</span>.bendstones ));
},
</pre>
</div>
Since they might be needed by the graphing functionality
each "calcProperty" method needs all the input parameters to be passed
and doesn't attempt to use them from the class. For completeness, here's
calcbendforce:<br />
<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;">calcbendforce <span style="color: #333333;">:</span> <span style="color: #008800; font-weight: bold;">function</span> ( tension, semitones ) {
<span style="color: #008800; font-weight: bold;">var</span> bendforce <span style="color: #333333;">=</span> tension <span style="color: #333333;">*</span> (<span style="color: #007020;">Math</span>.pow(<span style="color: #0000dd; font-weight: bold;">2</span>, semitones<span style="color: #333333;">/</span><span style="color: #0000dd; font-weight: bold;">6</span>) <span style="color: #333333;">-</span> <span style="color: #0000dd; font-weight: bold;">1</span>);
<span style="color: #008800; font-weight: bold;">return</span> bendforce;
}
</pre>
</div>
So either an update to the string tension or semitones
(number of semitones to bend) needs to update the bendforce. In this
particular model there's a hierarchy of variables that control others,
so it's possible to have each parameter only need to update the next
parameter in the chain.<br />
<h3>
Stringing it up</h3>
The interface is a fairly straightforward HTML
page with Dojo input and display boxes attached to elements. To get it
to talk to the physics model (which is defined as a Dojo class) each
input object can be given a callback to run when the value is updated in
the interface and can set a callback on the physics object to allow it
to update the interface. Some elements don't depend on anything (like
scale), so they don't set the callback in the physics object. Others
can't be set and can only be updated as the result of other changes
(like bend distance), so they don't use the set method.<br />
String tension can both be set directly (bypassing the tension calculations) and updated by other changes:<br />
tension_box is a "dijit/form/NumberSpinner" assigned to the element name "tension":<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;">tension_box <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">new</span> Spinner({
onChange<span style="color: #333333;">:</span> tension_updated
<span style="color: #888888;">// other parameters</span>
}, <span style="background-color: #fff0f0;">"tension"</span>);
</pre>
</div>
tension_updated is a function which will update the wire tension when the value in the input box is being changed: <br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;">tension_updated <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> () {
<span style="color: #008800; font-weight: bold;">if</span> (tension_box.focused) {wire.set_tension(tension_box.get(<span style="background-color: #fff0f0;">"value"</span>));}
};
</pre>
</div>
The "wire" callback is set so it can update the tension
(for elements that are not input boxes the function can instead set the
element value directly) when it changes in the model. Checking whether
the box is focused prevents the callback trying to update the box while
it's being edited.<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;">wire.cb_updated_tension <span style="color: #333333;">=</span> <span style="color: #008800; font-weight: bold;">function</span> (){
<span style="color: #008800; font-weight: bold;">if</span> (<span style="color: #333333;">!</span>tension_box.focused) {tension_box.set(<span style="background-color: #fff0f0;">"value"</span>,wire.tension);}
};
</pre>
</div>
And finally this has to appear somewhere, I've collected them in a startup function:<br />
<div style="background: rgb(255, 255, 255) none repeat scroll 0% 0%; border-width: .1em .1em .1em .8em; border: medium solid gray; overflow: auto; padding: 0.2em 0.6em; width: auto;">
<pre style="line-height: 125%; margin: 0px;">tension_box.startup(); </pre>
</div>
Odd things happen if you forget to startup a widget, it may initialise controls, but refuse to honour settings like size.<br />
<h3>
Progression</h3>
In <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-1-maths-rock.html">part 1</a> I mentioned that things were done in terms of tension. You can eliminate calculating the tension if you just want the bend distance, but since it's something that might be interesting (for string sets, or knowing how much harder a certain setup is to bend) instead a lot of the model works by finding the tension and using it to find the other numbers.<br />
<ol>
<li>Scale, string gauge, density and note are all used to calculate tension.</li>
<li>The bend tonal distance is used to find how much extra tension is needed.</li>
<li>Total string length (including past headstock), stiffness, gauge and bend tension are used to find the length stretch.</li>
<li>Length stretch is used to find the sideways stretch.</li>
<li>The sideways bend force needed is found using the total tension, sideways stretch and scale length.</li>
</ol>
Because of this it's also possible to update the tension independently to see what happens to the later numbers. For example maybe you're using the manufacturer's force numbers for a particular string set. <br />
<h3>
Graphs and hair loss</h3>
The graphs are done with Dojo's "Chart"
widget, using the Lines type ("dojox/charting/plot2d/Lines"). One thing
school science lessons should have drummed into you is that you need to
label the axes on graphs. And this one isn't very useful: <br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-waN_Ex6_xVI/Ug80CzEddII/AAAAAAAAAeM/vvdmdhRqPuI/s1600/brokenplot.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/-waN_Ex6_xVI/Ug80CzEddII/AAAAAAAAAeM/vvdmdhRqPuI/s1600/brokenplot.png" width="295" /></a></div>
What
is the bend force for 25"? It's probably more than 24.5", but we can't
even say that for sure, I might have gone crazy (or made a strange
mistake) and put the scale upside down. I did ask it for labels (the
"title" parameter). The problem turns out to be automatic ranges, if you
don't give a "min" and "max" for the axes range, Dojo tries to
calculate it from the data series you've given it.<br />
I was starting
the charts with an empty series to be filled in on the first update, the
"scale length" x axis is okay, we can give it min and max since it
doesn't change, but y needs to be automatic. Since Dojo can't guess and
hasn't been given a range to start with it doesn't leave enough space
for it once it gets the data. The solution is to generate the data when the chart is first created. Final result:<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-FcfcJxDGxkA/Uhf7gIabTfI/AAAAAAAAAeo/VvbL0cfAbWA/s1600/goodplot.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-FcfcJxDGxkA/Uhf7gIabTfI/AAAAAAAAAeo/VvbL0cfAbWA/s1600/goodplot.png" /></a></div>
<h3>
Hosting</h3>
Finally
a quick note on hosting. At the time of writing it's 2013 and like many
people I'm writing on a (free) web service. You can do all kinds of
things with plugins, but just try deploying your own Javscript, or
(actually worse) your own web page. Getting Javascript hosted by blogger
or google sites is possible if you run through hoops, but if you need
to go down this road and are happy to put your code under an open source
license then <a href="http://code.google.com/" target="_blank">Google Code</a> is probably the simplest solution.<br />
To
use Dojo to do the page layout you need your own .html file, and that
rules out most free websites and blogging. I've ended up using
paid-for-hosting that I already had, but one interesting alternative is <a href="http://aws.amazon.com/s3" target="_blank">Amazon Web Services S3</a>
which can host static content and provides 5GB free for the first year
(though you need a credit card), even after a year hosting a few MB of
JS (or even a few hundred) should cost less than a pound per year.<br />
The finished product can be found at <a href="http://www.imalone.co.uk/stringbendcalc.html" target="_blank">http://www.imalone.co.uk/stringbendcalc.html</a>.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-56672155734377318522013-08-24T03:09:00.004+01:002022-03-22T16:05:10.493+00:00Bending with Dojo part 3: Slight returnThis is the last of three posts about building the <a href="http://www.imalone.co.uk/stringbendcalc.html" target="_blank">string bend calculator</a> and maybe the most interesting to anyone other than me. <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-1-maths-rock.html">Part 1</a> dealt with the basic physics and <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-2-stretching-in.html">Part 2</a> with building the Javascript app. All that's left is to wonder what it all means.<br />
<br />
<a name='more'></a><br /><br />
<script src="https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG"></script>
<script src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG"></script>The first thing to say is that when you bend a note the string does stretch and the stretch accounts the distance you have to push the string at the fret. How can I be sure? Looking at the numbers that first come up (for the high E string), the total tension is about 58N (Newtons, about the weight of 6 kilos or 13 pounds).<br />
Since the length does not change very much we have to increase the tension to increase the note. A full tone (2 semitone) bend needs the tension to go up by \(2^{(2/12)} \approx 1.12 \) times, to about 65.1N. Increasing the tension that much causes the string to stretch by a small amount, 1.2mm, and over the scale length of the guitar that small amount allows you to pull it sideways in the middle by a larger amount, 19.7mm (Pythagoras theorem).<br />
<h3>
Constant stretch</h3>
Try scrolling the string gauge up and down. String forces change, but watch the stretch distance: it stays the same. This isn't an error, if you look back at "Stretch it" in <a href="http://epenguin.imalone.co.uk/2013/08/bending-with-dojo-part-1-maths-rock.html">part 1</a>:<br />
\[\frac{T}{A}=E\frac{s}{L} \\<br />
(2fl)^2 = \frac{T}{\rho} \]<br />
But \(\rho=Ad\), so A, the part that depends on gauge, could be taken out, and whatever gauge the strings are they will be stretched by the same distance to get up to tuned pitch, and by the same extra distance to get to the bent note. (But this goes wrong for wound strings.)<br />
If you're protesting this is clearly wrong because thicker strings are harder to bend, then of course they are, but it's because the tension they're under is higher, not because you bend them further.<br />
<h3>
Forcing</h3>
The sideways bend force has to balance the sideways component of the string tension. The further you bend the string the more you are pulling "head-on" against the string tension (actually, against the tension at both ends), the standing tension of the strings contributes most of this force. This is why drop-tuning makes so much difference to string bending.<br />
<h3>
Strings past headstock</h3>
The string distance past headstock increases the bend force needed. This is because there's more string stretching, and the slack is pulled between the nut and bridge. You have to bend further and this makes the angle a bit sharper. Since the sideways force you apply balances the sideways force of the string bending further means <br />
<h3>
Things that are wrong</h3>
Like any model things have been simplified a bit, so what's wrong here?<br />
<ol>
<li>Tremolos. If you have a floating tremolo then it provides a bit of give when you apply the extra tension too, so expect more stretch, however the trem springs are quite stiff by comparison to the full length guitar string. The effect is like the 'extra length' string past the headstock. A 'screwed down' tremolo takes some force before it lifts, and until it does start to move it will act like a hard tail (for stretch purposes anyway).</li>
<li>String past headstock. We have completely ignored friction at the nut, which will reduce the effect of the extra stretch a little.</li>
<li>Density and wound strings. Wound strings are a bit lower density than
solid strings, but also the windings don't contribute anything to the
string stiffness. Only the core counts for stiffness. It would be
possible to have separate gauges for windings and core, instead I've
used a modified 'density' number that gives the right tensions for wound
strings.</li>
</ol>
Actually this gives a good insight into why there are wound strings. You want to have the tension about the same in all strings (balanced across the neck), but you also want them to have similar degrees of stretch. This is partly for feel, but mostly because strings stretched to about half their elastic limit will be at their most linear (well-behaved...). We've seen changing gauge has no effect on the actual string stretch needed to get to pitch, but only because the density and stiffness both depend on it. By using a wound core you can break that rule and tweak density and stiffness independently.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-87327802201664538022013-05-25T00:02:00.001+01:002022-03-22T16:05:39.275+00:00...And the Gods Made GuitarsA while ago, after spending far too much time on guitar forums, I decided to try building one myself. There are a number of ways to do this, the most adventurous involves finding an axe and a likely tree, but you don't have to go to those lengths.<br />
<a name='more'></a>In my <a href="http://ibmalone.blogspot.com/2013/05/steam-powered-guitars.html">last post</a> I mentioned the straightforward bolted-together construction of the Telecaster. With well-made parts the tele is probably the easiest guitar to put together. <br />
What finally persuaded me to try building one was that I could pick the features I wanted. I'd previously tried both the Squier <a href="http://www.fender.com/squier/series/classic-vibe/classic-vibe-telecaster-50s-butterscotch-blonde/" target="_blank">Classic Vibe Telecaster</a> and the Fender <a href="http://www.fender.com/en-GB/series/standard/standard-telecaster-maple-fingerboard-black-no-bag/" target="_blank">Standard Telecaster</a>, both are good (I got on with the Squier a bit better), but there are things I'd want to change on both too. Since this isn't my main guitar I could risk experimenting a bit.<br />
The classic telecaster has an ash or alder body with a maple neck, a steel bridge plate with three brass barrel saddles and two single coil pickups. Never having liked the traditional telecaster finishes (solid colour or the very opaque butterscotch-blonde), I'd been inspired to try finishing the body myself.<br />
<h3>
Wood</h3>
Yes, the body. If you're going to finish the body yourself you need to start with an unfinished one. <a href="http://guitarbuild.co.uk/" target="_blank">Guitarbuild.co.uk</a> will make custom bodies to order, but they also sell their popular designs on eBay as <a href="http://stores.ebay.co.uk/guitarbuilduk" target="_blank">woodwoo2</a> (unfortunately their courier is expensive for shipping to Northern Ireland, but mainland UK is okay).<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-b7MeN1yRSEY/UZ_UXyrvZsI/AAAAAAAAAa0/0vpHBn0rQ7c/s1600/DSCN5618_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/-b7MeN1yRSEY/UZ_UXyrvZsI/AAAAAAAAAa0/0vpHBn0rQ7c/s1600/DSCN5618_s.JPG" width="240" /></a></div>
For the finish I knew I wanted to try out <a href="http://www.wudtone.com/" target="_blank">Wudtone</a>. They're a Welsh outfit who make custom guitars, but also sell a few components, including a range of body finishing kits. It was tempting to try a green guitar, but I decided the body I was using would go better with <a href="http://www.wudtone.com/shop/?wpsc-product=finishing-kit-burning-sun" target="_blank">burning sun</a>...<br />
<a href="http://3.bp.blogspot.com/-k5KaEgKMTnE/UZ_UX4digSI/AAAAAAAAAa4/eubCEbO6A3U/s1600/DSCN5667_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/-k5KaEgKMTnE/UZ_UX4digSI/AAAAAAAAAa4/eubCEbO6A3U/s1600/DSCN5667_s.JPG" width="240" /></a>With an alder body and a wudtone kit I set to work with the steel wool and a spare tea-towel. <br />
<h3 style="clear: both;">
Steel </h3>
While the body was in preparation it was time to prepare the rest of the parts. I wanted to go for the classic all-maple neck and, though a flatter radius was briefly in the running (in the UK <a href="http://www.northwestguitars.co.uk/" target="_blank">Northwest Guitars</a> have a good reputation for doing custom necks fairly cheaply), decided on the modern tele 9.5" radius, to be a bit different from my current guitar. It did seem worth going for 22 frets though (because you're at 21 frets and where are you going to go?), so the neck is a Mighty Mite from <a href="http://axecaster.co.uk/" target="_blank">Axecaster</a>.<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-SwfzHMpOHgw/UZ_UXyfZoQI/AAAAAAAAAas/B98VmwWlyNQ/s1600/DSCN5693_s.JPG" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://3.bp.blogspot.com/-SwfzHMpOHgw/UZ_UXyfZoQI/AAAAAAAAAas/B98VmwWlyNQ/s1600/DSCN5693_s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Drilling for Wilkinson locking tuners</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-C1BaIyA3iAM/UZ_UZgg8kMI/AAAAAAAAAbU/kUuyQG89SeU/s1600/DSCN5720_s.JPG" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://2.bp.blogspot.com/-C1BaIyA3iAM/UZ_UZgg8kMI/AAAAAAAAAbU/kUuyQG89SeU/s1600/DSCN5720_s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">If you don't have a drill press then a<br />
dremel tool and a steady hand will do.</td></tr>
</tbody></table>
Another modern touch is going to be the bridge. The traditional tele has three barrels, so strings are intonated in pairs. Instead I wanted to use a 6-saddle bridge. Here it gets tricky, the traditional bridge and modern have different screw placement to mount onto the body and the Guitarbuild body is drilled for a traditional one. Fortunately I found Axecaster sell a modern 6-saddle bridge with traditional screw placement, but this would be an easy mistake to make in planning.<br />
The last major pieces still missing are the pickups. To keep the budget down, and because I've liked their other pickups in the past, I went with Irongear.<br />
<h3 style="clear: both;">
Rock</h3>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><br />
<a href="http://2.bp.blogspot.com/-uAWaME0jXPQ/UZ_UZ35-YUI/AAAAAAAAAbc/RvQsNz7Pg-E/s1600/DSCN5723_s.JPG" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://2.bp.blogspot.com/-uAWaME0jXPQ/UZ_UZ35-YUI/AAAAAAAAAbc/RvQsNz7Pg-E/s1600/DSCN5723_s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Shielding and hardware in place,<br />
drilling for the pickguard</td></tr>
</tbody></table>
...that's not quite the whole story. When I saw these: <a href="http://www.irongear.co.uk/irongear_026.htm" target="_blank">IronGear Steel Twin-II</a>, it was one of the things I wanted on the guitar from the very start. These are high output coil-taped telecaster pickups, so you can have them mellow and then kick in the high-octane. The wiring diagram is not complicated, just IronGear's suggested wiring, though I've changed the tone pot to log and the tone capacitor to a more subtle .033uF (just to try, Axecaster again). Most of the electronics and other hardware (strap-buttons, jack socket and plate, electronics cover, pots, copper shielding, switch, and switch and pot tips and knobs) came from <a href="http://www.axetec.co.uk/" target="_blank">Axetec</a>.<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-yALEew83YUQ/UZ_UYwtql1I/AAAAAAAAAbA/7pb3qH9PGKw/s1600/DSCN5702_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="150" src="http://3.bp.blogspot.com/-yALEew83YUQ/UZ_UYwtql1I/AAAAAAAAAbA/7pb3qH9PGKw/s1600/DSCN5702_s.JPG" width="200" /></a></div>
DIY of course stands for "Destroy It Yourself," it isn't a DIY project unless something goes terribly wrong. In this case trying to get an over-wound pickup through a bridge plate with a sharp edge. When you see the tape pulled off with broken wire on it you're having a bad day.<br />
<a href="http://3.bp.blogspot.com/-fjj6OqYAZ-E/UZ_UZMuhyEI/AAAAAAAAAbI/jh8rrm0VVOM/s1600/DSCN5709_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="150" src="http://3.bp.blogspot.com/-fjj6OqYAZ-E/UZ_UZMuhyEI/AAAAAAAAAbI/jh8rrm0VVOM/s1600/DSCN5709_s.JPG" width="200" /></a>The next morning was spent unwinding the pickup, in the hope of getting back to the break. There turned out to be three, by the time I'd finished the bridge pickup was down from 16.1k to 12.6k, but after some tricky soldering we were back in business.<br />
<div style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-lI2h-QRqfEs/UZ_Uaxoj34I/AAAAAAAAAb0/BESpJUYmNm4/s1600/DSCN7029_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://2.bp.blogspot.com/-lI2h-QRqfEs/UZ_Uaxoj34I/AAAAAAAAAb0/BESpJUYmNm4/s1600/DSCN7029_s.JPG" width="240" /></a></div>
Before trying again I attacked the bridge plate with an engineer's file
and some sandpaper (from underneath to avoid scratching it). If you ever
find yourself fitting a telecaster bridge I'd recommend doing that
until you're certain it's going to fit.<br />
If there's one complaint about the telecaster design, you can't get at the bridge pickup without taking the bridge plate off. On a block-saddle bridge you can't do that without taking the saddles and the strings off too, so be sure you're happy before putting them on.<br />
If there's a second complaint it's that with a 22-fret neck you can't take the pick-guard off without talking the neck off. Since that's ridiculous I re-cut and filed down the neck slot on the pick-guard.<br />
<h3 style="clear: both;">
Sparks</h3>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-y1qgmDHfyrs/UZ_UaLZbPfI/AAAAAAAAAbY/D69gi7yEOws/s1600/DSCN5810_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="http://2.bp.blogspot.com/-y1qgmDHfyrs/UZ_UaLZbPfI/AAAAAAAAAbY/D69gi7yEOws/s1600/DSCN5810_s.JPG" width="320" /></a></div>
<a href="https://4.bp.blogspot.com/-eeqTGeYqT2g/UZ_UasPa2-I/AAAAAAAAAbs/SInvdyfDDis/s1600/DSCN5813_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="http://4.bp.blogspot.com/-eeqTGeYqT2g/UZ_UasPa2-I/AAAAAAAAAbs/SInvdyfDDis/s1600/DSCN5813_s.JPG" width="320" /></a><br />
At least the wiring is simple, unlike the strat the tele has a separate compartment and cover for this. With all the shielding in place I tried doing it by wiring the pickups into barrier strips (screw terminals) to connect to the soldered control module. Getting this into the cavity is a bit of a squeeze, but it means when you discover the pickup switch is the wrong way around (yes), changing it is a five minute job with a screwdriver.<br />
<br />
<h3 id="light" style="clear: both;">
Let there be light...</h3>
<a href="http://4.bp.blogspot.com/-efEO8e5X8fU/UZ_UbOPexzI/AAAAAAAAAbw/VZaQA5qyvVE/s1600/DSCN7033_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://4.bp.blogspot.com/-efEO8e5X8fU/UZ_UbOPexzI/AAAAAAAAAbw/VZaQA5qyvVE/s1600/DSCN7033_s.JPG" width="240" /></a>The last task (apart from a bit of setting-up) is naming it. After a bit of thought, the burning sun and black scheme made me think of dawn, so it's named for the Greek dawn goddess/titaness, <a href="http://en.wikipedia.org/wiki/Eos" target="_blank">Eos</a>. Doubly appropriate since most of the work was done at Easter which is probably named after her German equivalent <a href="http://en.wikipedia.org/wiki/Eostre" target="_blank">Eostre</a>.<br />
The transfer is from <a href="http://shop.rothkoandfrost.co.uk/" target="_blank">Rothko and Frost</a>. Despite lacquering and sanding, the surround hasn't turned out invisible, but in most light it's good enough.<br />
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
The finished product. It spends most of its time about 300 miles away, so I haven't managed to record a good sample yet. The sound goes from glassy to woody. As you might expect with half the extra windings on the bridge pickup removed the extra kick is less impressive than it might be, but I'm happy with how Eos turned out. Doing this with decent parts wont save you any money (a Squier CV would be cheaper), but it's an interesting (sometimes hair-pullingly frustrating) way to get to know your guitar.<br />
<div class="separator" style="clear: both; text-align: center;">
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<a href="http://2.bp.blogspot.com/-1gW5R7I9rwk/UZ_UcLeToXI/AAAAAAAAAcE/1XCpkd_67yA/s1600/DSCN7055_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://2.bp.blogspot.com/-1gW5R7I9rwk/UZ_UcLeToXI/AAAAAAAAAcE/1XCpkd_67yA/s1600/DSCN7055_s.JPG" width="240" /></a></div>
<a href="http://4.bp.blogspot.com/-25-PteNMzhU/UZ_Ub2hdekI/AAAAAAAAAcA/nwP_FtgDcWM/s1600/DSCN7036_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://4.bp.blogspot.com/-25-PteNMzhU/UZ_Ub2hdekI/AAAAAAAAAcA/nwP_FtgDcWM/s1600/DSCN7036_s.JPG" width="240" /></a>
<!--Blogger automated replacement: "https://images-blogger-opensocial.googleusercontent.com/gadgets/proxy?url=http%3A%2F%2F4.bp.blogspot.com%2F-eeqTGeYqT2g%2FUZ_UasPa2-I%2FAAAAAAAAAbs%2FSInvdyfDDis%2Fs1600%2FDSCN5813_s.JPG&container=blogger&gadget=a&rewriteMime=image%2F*" with "https://4.bp.blogspot.com/-eeqTGeYqT2g/UZ_UasPa2-I/AAAAAAAAAbs/SInvdyfDDis/s1600/DSCN5813_s.JPG"-->justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-11701699760911022422013-05-20T03:28:00.001+01:002022-03-22T16:05:46.898+00:00Steam powered guitars<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/SteampunkPendant.jpg/320px-SteampunkPendant.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/SteampunkPendant.jpg/320px-SteampunkPendant.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Vaughn and Sean Saball's <a href="http://commons.wikimedia.org/wiki/File:SteampunkPendant.jpg" target="_blank">Steampunk heart</a></td></tr>
</tbody></table>
Even if you haven't heard of steampunk you've probably seen it, recently I found myself wondering what a steampunk guitar might look like.<br />
<a name='more'></a><br />
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Steampunk is what we imagine the future looked like at the height of the industrial age; if Isambard Kingdom Brunel and Charles Babbage had started Google the world would be something like this, with machinery covered in cogs, pipes and valves. (Of course, in the same way <a href="http://xkcd.com/1211/" target="_blank">birds are dinosaurs</a>, modern technology is what Victorian technology became; IBM is over 100 years old.)<br />
While it began as a literary genre, steampunk ideas have gradually pushed into mainstream culture; Sherlock Holmes faces villains with remote controlled bombs, Van Helsing uses an automatic crossbow (which Hansel and Gretel seem to have borrowed), a charge that might have been led by Doc Brown's flying train from Back to the Future.<br />
<br />
Where do guitars fit into this? The modern guitar player is often a bit of a traditionalist, Les Pauls and Stratocasters date back to the 50's, what we think of as a modern instrument is over 60 years old and, aside from ultra-modern design like the Variax, the basics are still the same: a piece of wood, a magnet and lots of coils of wire. Few other instruments make sound by manipulating electromagnetic fields and, aside from the theremin, the electric guitar is probably the one modern instrument that James Maxwell, Nikola Tesla, et al. would immediately understand. It wouldn't be very out of place to find one in a 19th century workshop.<br />
The steampunk tendency to put pipes on things might suggest something like the amazing <a href="http://www.hutchinsonguitars.com/concepts/steampunk-sp-1/" target="_blank">Hutchinson SP-1</a>, but you could argue for a much simpler appearance.<br />
For a long time I didn't like how one classic guitar looked, there was something unfinished, even a little industrial about it compared to the space-age Stratocaster or beautifully crafted Les Paul. Which is ironic, since even its name comes from the very start of the space age, the Fender Telecaster was built in 1950 by Leo Fender, but only the powerful magnets (AlNiCo was discovered in 1931) mean you wouldn't have seen one in <a href="http://en.wikipedia.org/wiki/The_Great_Exhibition" target="_blank">The Great Exhibition</a>.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-syq9KUpWTnE/UZmJBr7rnYI/AAAAAAAAAaM/etrbsO-xs9w/s1600/Telecaster_bridge_crop.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://3.bp.blogspot.com/-syq9KUpWTnE/UZmJBr7rnYI/AAAAAAAAAaM/etrbsO-xs9w/s1600/Telecaster_bridge_crop.jpg" width="313" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Brass and steel on the classic bridge (<a href="http://commons.wikimedia.org/wiki/File:Telecaster_bridge.jpg" target="_blank">Wikimedia</a>)</td></tr>
</tbody></table>
The large steel plate holding down the bridge, the chunky simple body outline and bolt-on neck all speak of the same belt-and-braces approach to engineering that led to Hammersmith Bridge.<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-rQlfxwqUKdw/UZmEP8lWBGI/AAAAAAAAAZ4/xO7IDiNnbJk/s1600/DSCN5831_bridgecrop.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" height="257" src="http://4.bp.blogspot.com/-rQlfxwqUKdw/UZmEP8lWBGI/AAAAAAAAAZ4/xO7IDiNnbJk/s1600/DSCN5831_bridgecrop.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The modern Telecaster bridge</td></tr>
</tbody></table>
(That Hammersmith bridge has spent most of its history on the verge of falling down is probably best forgotten...)<br />
<br />
Amplification would have had to wait a while, or maybe some kind of stream-powered organ could have been rigged up, but the Telecaster would have been right at home in a dressing room recital, possibly accompanying a <a href="http://en.wikipedia.org/wiki/Stroh_violin" target="_blank">Stroh violin</a>. The Tele doesn't need clockwork to be a steampunk dream. Like the birds, Victorian technology evolved, but like them too, every electric guitar still shows its heritage and a few of of them still have claws.<br />
<span face="Arial,Helvetica,sans-serif"><b>Update:</b></span><br />
If you still feel more brass cogs are needed to be really steampunk it might be worth checking out <a href="http://www.flickr.com/photos/pauldineen/galleries/72157622469463309" target="_blank">this flickr gallery</a> or <a href="http://www.techeblog.com/index.php/tech-gadget/10-cool-and-creative-steampunk-guitars-guns" target="_blank">techeblog's article</a>.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-86272048785729108742013-03-05T00:55:00.003+00:002022-03-22T16:06:00.217+00:00Fedora, Living the Jam<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-wKSahgEnMEM/UTU6kbGsmqI/AAAAAAAAAY0/114jUthpxtw/s1600/DSCN5563-sc.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://2.bp.blogspot.com/-wKSahgEnMEM/UTU6kbGsmqI/AAAAAAAAAY0/114jUthpxtw/s1600/DSCN5563-sc.JPG" width="240" /></a></div>
<a href="http://get.fedoraproject.org/" target="_blank">Fedora 18</a> was released on 15th January, and anyone eagerly awaiting <a href="http://epenguin.imalone.co.uk/2012/11/cooking-jam.html" target="_blank">Jam </a>might be wondering how to get it. Fedora Jam was ready for the Fedora 18 release, but it didn't make it into the official release discs, you can instead get a preview of Fedora 19 Jam by following the instructions at the <a href="https://fedoraproject.org/wiki/Fedora_jam#Kickstart.2FISO_File" target="_blank">Jam wiki page</a>. After a month and a half, how is the Jam looking? Here is a <a href="http://ibmalone.blogspot.com/2013/03/fedora-living-jam.html#more">quick look at the Jam and a few tips for getting the best out of it</a>.<br />
<a href="http://4.bp.blogspot.com/-4hquIX3Zm_M/UTUfwJA1edI/AAAAAAAAAXE/QnvvgSZEGcc/s1600/Desktop-layout-sc.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"></a><br />
<a name='more'></a>Most of the interesting things in Fedora Jam can be found under the Multimedia and Multimedia Creation menus. Particularly in 'Sequencers' you'll find digital audio workstations (DAWs) including Ardour. The Jack session manager, QJackCtl, has its own shortcut in the Favourites menu.<br />
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<a href="http://4.bp.blogspot.com/-KyU6Jtg7ap8/UTUi8t3O4AI/AAAAAAAAAXU/GJhuCvkDGOg/s1600/sw-creation-crop-sc.png" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="http://4.bp.blogspot.com/-KyU6Jtg7ap8/UTUi8t3O4AI/AAAAAAAAAXU/GJhuCvkDGOg/s1600/sw-creation-crop-sc.png" /></a><a href="http://3.bp.blogspot.com/-puj-8fDHVyE/UTUi8xYbczI/AAAAAAAAAXY/Iw8ak_p3Yp0/s1600/sw-multimedia-crop-sc.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="http://3.bp.blogspot.com/-puj-8fDHVyE/UTUi8xYbczI/AAAAAAAAAXY/Iw8ak_p3Yp0/s1600/sw-multimedia-crop-sc.png" /></a></div>
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If you're new to KDE, that search box at the top of the application menu is useful if you know what you're looking for, but you can also just flick through the menus if you're after inspiration. Things soon look like this:<br />
<a href="http://4.bp.blogspot.com/-4hquIX3Zm_M/UTUfwJA1edI/AAAAAAAAAXE/QnvvgSZEGcc/s1600/Desktop-layout-sc.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="512" src="http://4.bp.blogspot.com/-4hquIX3Zm_M/UTUfwJA1edI/AAAAAAAAAXE/QnvvgSZEGcc/s1600/Desktop-layout-sc.png" width="640" /></a><br />
This very busy screenshot is a recording setup with Jack, Ardour and <a href="http://piorekf.org/plug/" target="_blank">Plug</a> for <a href="http://epenguin.imalone.co.uk/2012/04/breaking-in-fender-mustang.html" target="_blank">Fender Mustang amplifiers</a>. Plug is now packaged in Fedora and all you need to do is install the program from Software Management before you connect the amplifier. I've set Jack up as in the instructions <a href="https://fedoraproject.org/wiki/JACK_Audio_Connection_Kit#Integrate_JACK_with_PulseAudio" target="_blank">to have PulseAudio redirected to use JACK</a> (option #3 there). Ardour's click track is turned on, it's not immediately obvious how to set the tempo:<br />
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<a href="http://4.bp.blogspot.com/-PfU2iVYE3Ig/UTUp6ADGNKI/AAAAAAAAAXw/B9f4WsWr3wQ/s1600/Ardour-tempodialog-sc.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="216" src="http://4.bp.blogspot.com/-PfU2iVYE3Ig/UTUp6ADGNKI/AAAAAAAAAXw/B9f4WsWr3wQ/s1600/Ardour-tempodialog-sc.png" width="320" /></a></div>
Right click on red track next to the 'tempo' to set... the tempo! I
think you can also use this slider to set tempo changes during the
piece.<br />
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You can do the same with the 'meter bar'.</div>
<a href="http://2.bp.blogspot.com/-QlxcRiHep9w/UTUp6IPowSI/AAAAAAAAAXs/8w-MExs-pLo/s1600/Ardour-meterdialog-sc.png" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="216" src="http://2.bp.blogspot.com/-QlxcRiHep9w/UTUp6IPowSI/AAAAAAAAAXs/8w-MExs-pLo/s1600/Ardour-meterdialog-sc.png" width="320" /></a>
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A click track is one thing, but you might want to use a reference track instead. Of course you can import this or record it separately, but there's another trick you can do if you want to record from something like Skype or Youtube while recording your own mic or instrument.<br />
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<a href="http://3.bp.blogspot.com/-aMx9nW-Pnq8/UTUtQYYoGHI/AAAAAAAAAYE/-4-QUsJmqho/s1600/Ardour-refsetup2-sc.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="512" src="http://3.bp.blogspot.com/-aMx9nW-Pnq8/UTUtQYYoGHI/AAAAAAAAAYE/-4-QUsJmqho/s1600/Ardour-refsetup2-sc.png" width="640" /></a></div>
This isn't as complicated as it looks! I've added two buses to the Ardour session and set both to record (the guitar track is mono). I've also named them because it makes working out the connections simpler.<br />
In QJackCtl the 'system capture' is routed to 'Guitar/in 1' in Ardour, the pulseaudio outputs are connected to the Ref/in channels 1 & 2. At the bottom right you can see pavucontrol (the pulseaudio volume control), I've opened this to make sure the output from the source for my reference track is using the 'Jack sink'. Remember you can look at the Ardour level meter to see that recording tracks are picking up input.<br />
Finally, so I can hear everything through headphones, both 'system capture' and 'pulseaudio JACK sink' are also connected to system playback.<br />
<h3>
Beyond recording</h3>
Arguably the strength of Fedora Jam is in the tools for composition and digital music creation. There is a wide range of synthesizers and sequencers available, and even a non-expert like me can get them up and running without too much fuss. Here's Rosegarden:<br />
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<a href="http://4.bp.blogspot.com/-kkE7zpxlOjw/UTUx0gVxcqI/AAAAAAAAAYU/RsyeVEU5xy8/s1600/rosegardenexample-sc.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="460" src="http://4.bp.blogspot.com/-kkE7zpxlOjw/UTUx0gVxcqI/AAAAAAAAAYU/RsyeVEU5xy8/s1600/rosegardenexample-sc.png" width="640" /></a></div>
This is a fairly simple set-up, with no Midi connections, just using a plugin-synthesizer. While the Rosegarden interface is (like most sequencers) quite busy all I've done here is:<br />
<ol>
<li>Click on track 1.</li>
<li>Changed 'device' from 'General midi device' to 'synth plugin'</li>
<li>Clicked on 'no synth' in the 'instrument parameters' and selected 'Xsynth' instead, close the menu that comes up. (You can get those controls and the instrument selection again by clicking on 'Editor'.)</li>
<li>Click in the sequencer window (next to track 1 "<untitled>") to create a segment, then right click on it to get the matrix editor.</li>
</ol>
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<a href="http://3.bp.blogspot.com/-eANIRuZF6Bc/UTUz5NyhloI/AAAAAAAAAYk/JkTV1loXyUI/s1600/rosegardenarpeggio-crop-sc.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="330" src="http://3.bp.blogspot.com/-eANIRuZF6Bc/UTUz5NyhloI/AAAAAAAAAYk/JkTV1loXyUI/s1600/rosegardenarpeggio-crop-sc.png" width="400" /></a></div>
Then in the editor I've just done a simple arpeggio. Use QJackCtl to connect Rosegarden up to Jack and then click play. If you want to drive your neighbours mad then you can set this segment to repeat (see top left). To learn more see the <a href="http://www.rosegardenmusic.com/wiki/doc:manual-en" target="_blank">Rosegarden manual</a>.<br />
Or, if you just want to try something cool, open <a href="http://musescore.org/" target="_blank">MuseScore</a> and click play...<br />
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<a href="http://4.bp.blogspot.com/-tI2DUblv0ec/UTU72d-tkSI/AAAAAAAAAY8/WGJZrxZ2Hak/s1600/MuseScore+Reunion_018.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="263" src="http://4.bp.blogspot.com/-tI2DUblv0ec/UTU72d-tkSI/AAAAAAAAAY8/WGJZrxZ2Hak/s1600/MuseScore+Reunion_018.JPG" width="320" /></a></div>
Skimming over all the other tools, <a href="http://www.hydrogen-music.org/hcms/" target="_blank">Hydrogen</a> drum machine, <a href="http://www.rncbc.org/drupal/" target="_blank">V1 Suite</a>, <a href="http://non.tuxfamily.org/" target="_blank">NON</a>, <a href="http://guitarix.sourceforge.net/" target="_blank">Guitarix</a>, <a href="http://rakarrack.sourceforge.net/" target="_blank">Rakarrack</a>, many ladspa and lv2 plugins, and lots more, the last thing I'll mention is <a href="http://www.kde.org/applications/multimedia/dragonplayer/" target="_blank">Dragon Player</a>, which is just a simple media player, it's there because, sometimes, all you want to do is just play a track.</div>
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And there you are; Fedora, Jam today.<br />
<br />
<br /></div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com2tag:blogger.com,1999:blog-3637061929524336435.post-43680929935193585982013-02-11T01:01:00.001+00:002022-03-22T16:06:05.812+00:00Back to the old school...<div style="text-align: justify;">
Lately I've been going through a bit of a quiet period on the guitar front. Since I haven't been playing long I'm very aware I need to keep practising to improve, but how do you move forwards when you find yourself aimlessly noodling and repeating things you already know? Well of course you try and change your routine, so the book that's on my music stand now is Mel Bay's Deluxe Enyclopedia of Guitar Chord Progressions.</div>
<a name='more'></a><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr><td style="text-align: center;"><img border="0" height="320" src="http://1.bp.blogspot.com/-syHYKqFL8P4/URg5V6g3gXI/AAAAAAAAAWo/NCaStb1R9kg/s1600/DSCN5480_s_crop.JPG" style="margin-left: auto; margin-right: auto;" width="218" /></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Johnny Rector. Images copyright Mel Bay</td></tr>
</tbody></table>
<br />
<div style="text-align: justify;">
I was put onto this by a couple of posters at the <a href="http://www.guitarnoise.com/forums/viewtopic.php?f=9&t=53680&p=467080&hilit=imalone#p467101" target="_blank">GuitarNoise</a> forums. This is a guitar instruction book so venerable it has a <a href="http://en.wikipedia.org/wiki/Mel_Bay%27s_Deluxe_Encyclopedia_of_Guitar_Chords" target="_blank">Wikipedia Page</a>, though its roots seem to go back to Johnny Rector's <i>Guitar Chord progressions</i> book from 1956. Which would put it up there with Bert Wheedon's 1957 <i>Play In A Day</i>. My copy is a recent print, but seems to be a direct facsimile of the 1977 edition, complete with era-appropriate typesetting:</div>
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</div>
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</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-Puukee45yZM/URg4fFxW5sI/AAAAAAAAAWY/RvhMmwd919k/s1600/DSCN5481_s.JPG" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://1.bp.blogspot.com/-Puukee45yZM/URg4fFxW5sI/AAAAAAAAAWY/RvhMmwd919k/s1600/DSCN5481_s.JPG" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">The 70's: say it with capitals. Copyright Mel Bay</td></tr>
</tbody></table>
<div style="text-align: justify;">
Why use a book that's older than me and whose predecessor is older than my parents? Well, this is a really different approach to more modern books which give you pieces to play through to practice a scale or timing, or to learning from tab or YouTube which usually focuses on arrangements or techniques for a particular piece. All have their place, but to give myself a change of pace I'm going to be trying this for a while:</div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-HfC6yTtyP0Q/URg4fP01fiI/AAAAAAAAAWU/Zli3EsnhdiE/s1600/DSCN5482_s.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://1.bp.blogspot.com/-HfC6yTtyP0Q/URg4fP01fiI/AAAAAAAAAWU/Zli3EsnhdiE/s1600/DSCN5482_s.JPG" width="240" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">How many ways can you play one<br />
sequence? Copyright Mel Bay</td></tr>
</tbody></table>
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<br /></div>
<div style="text-align: justify;">
Basically the first half of this book is 'learn these chords and play this progression until you can do it in your sleep, now do it again a semitone up', with variations on each progression and a new progression each page. That sounds pretty dull, but getting chord changes down cold is important, and there are some weird chords in there; the very first exercise has 6th chord voicings I haven't seen in any beginners book. So while the process sounds dull the challenge isn't.</div>
<div style="text-align: justify;">
And if I do get bored at any point I have that quirky 70's American look to cheer me up. It's like being taught guitar by Hunter S. Thompson.</div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-27161046428163537812012-12-07T23:30:00.003+00:002022-03-22T16:06:13.178+00:00Taking the Pulse<div style="text-align: justify;">
As the<a href="http://fedoraproject.org/wiki/Fedora_jam" target="_blank"> Fedora Jam spin</a> rolls <a href="http://epenguin.imalone.co.uk/2012/11/cooking-jam.html" target="_blank">onwards</a>, a key component is Jack. The<a href="http://jackaudio.org/" target="_blank"> Jack Audio Connection Kit</a> (one of those recursive anagrams so popular in the mid 2000s...) is the glue that binds pro-sound in Linux together. It's used for <a href="http://ardour.org/" target="_blank">DAW</a>s, <a href="http://www.ladspa.org/" target="_blank">audio plugins</a>, <a href="http://guitarix.sourceforge.net/" target="_blank">real-time effects</a> processing and generally pushing sound around. To do this it has to play well with another Linux audio layer, <a href="http://www.freedesktop.org/wiki/Software/PulseAudio" target="_blank">PulseAudio</a>, and this is where the trouble starts.</div>
<a name='more'></a><b>Update 31 Jan 2012 Since this post was written a number of
patches have made it through to PulseAudio which may address this issue
in the next release (and importantly can be applied to versions already
out there). Watch this space...</b><br />
<br />
<b> </b>For the Jam spin we want pro-audio to work out of the box; why
shouldn't it? Anyone trying an audio creation platform is going to be a
bit surprised if they find out it isn't configured with sound working.
(If you're only here to get Jack working, just <a href="http://epenguin.imalone.co.uk/2012/12/taking-pulse.html#solution">skip to the end</a>).<br />
<br />
<div style="text-align: justify;">
Sound works in Linux: this isn't 2002. There's some rare hardware that isn't supported and the most cutting edge stuff can sometimes take a while to get drivers. On the other hand I had to hunt around to get a driver for my main soundcard for Windows 8, so the grass on both sides is sometimes in need of watering.</div>
<h3 style="text-align: justify;">
PulseAudio </h3>
<div style="text-align: justify;">
Sound works on the desktop, thanks both to the <a href="http://www.alsa-project.org/main/index.php/Main_Page" target="_blank">ALSA</a> developers and PulseAudio, which is the layer that channels sound from different programmes through to the soundcard. I like Pulse, because I remember what things were like before it, if you were lucky and messed around with sample rates and formats you could have two applications playing sound at once. Don't know what I'm talking about? Be glad you have Pulse.</div>
<div style="text-align: justify;">
But, to do its real-time, low-latency magic, Jack needs direct access to the sound card. That means getting Pulse to let go. You can still have Pulse and all the good things it gives you, because Jack can pretend to be a device for Pulse to use.</div>
<div style="text-align: justify;">
So everything is great.</div>
<div style="text-align: justify;">
Except...</div>
<h3 style="text-align: justify;">
Learning to let go</h3>
<div style="text-align: justify;">
Pulse is a bit possessive of audio devices. The problem it's meant to address is that only one programme can directly use an audio device at a time, pretty much like only being able to call one person on your phone at a time. Pulse solves that problem by being that programme and then combining the streams from everything else (a conference call in the phone analogy). But when something like Jack has a good reason to use the line instead it should hang up.</div>
<div style="text-align: justify;">
There's a way to ask it to. Since 2009 there's been a <a href="http://git.0pointer.de/?p=reserve.git;a=blob;f=reserve.txt" target="_blank">specification</a> for asking Pulse to let go of a sound card and Jack tries to do this.</div>
<h3 style="text-align: justify;">
Deaf ears</h3>
<div style="text-align: justify;">
In short Pulse is meant to put up a sign (virtually, not an actual message on the screen) for every device it's using. If something else wants to use that device it checks for the sign and if there isn't one it writes to Pulse asking it to let go (or, with our phone analogy, taps it on the shoulder politely). If Pulse isn't doing anything important then it lets go and takes down the sign. However, it's quite common for Pulse to put up the sign and stop listening to it. Other programmes (like Jack) see the sign, and when Pulse ignores them think it must be on an important call and give up.</div>
<h3 style="text-align: justify;">
Anatomy of a bug report</h3>
<div style="text-align: justify;">
This is a two line change to PulseAudio (the {} don't count):</div>
<div style="text-align: justify;">
<!--HTML generated using hilite.me--><br /></div>
<div style="background: white none repeat scroll 0% 0%; border: medium solid gray; color: black; overflow: auto; padding: 0.2em 0.6em; text-align: justify; width: auto;">
<pre style="line-height: 125%; margin: 0px;"><span style="color: #a00000;">--- a/src/modules/reserve.c</span>
<span style="color: #00a000;">+++ b/src/modules/reserve.c</span>
<span style="color: purple; font-weight: bold;">@@ -409,6 +409,10 @@ int rd_acquire(</span>
goto fail;
}
<span style="color: #00a000;">+ if (k == DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER) {</span>
<span style="color: #00a000;">+ goto success;</span>
<span style="color: #00a000;">+ }</span>
<span style="color: #00a000;">+</span>
if (k == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER)
goto success;
</pre>
</div>
<div style="text-align: justify;">
It looks simple (it is simple). Somewhere in the Pulse code it ends up checking whether a device it has a device it already owns. This is apparently a bug, but no-one currently knows where. If this happens Pulse gets confused and stops watching for messages to the sign.</div>
<div style="text-align: justify;">
In our phone analogy, Pulse suddenly thinks, "Where's my phone?" Failing to realise it's in its hand it then stands there, catatonic, while Jack stands beside it trying to be heard. If a person did this you'd consider them rude. Of course what it should do is realise it's holding the phone and carry on with life.</div>
<div style="text-align: justify;">
One of the reasons that many people still don't like Pulse is that when it first arrived there were plenty of problems, many were actually issues in other software, especially quirks in ALSA drivers that hadn't been important before. Somewhat justifiably the Pulse position was that these should be fixed at source, not worked around. Gradually, mainly with the hard work of ALSA developers, those bugs were fixed and for normal use it generally now works.</div>
<div style="text-align: justify;">
But, if you're going to take the position that other people should fix their interfaces then you shouldn't be surprised if they expect the same of you. Whatever the reason for Pulse to check up on itself, its module for listening to requests should survive that, there are too many ways for this kind of thing to happen in real code to intentionally keep fragile code in an interface.</div>
<h3 style="text-align: justify;">
Killing the Pulse</h3>
<div id="solution" style="text-align: justify;">
So things are broken and there's no hope? Do we give up on Jack in Fedora 18? Should you remove Pulse and leave your programmes huddled round your speakers jostling for a chance to speak? No, the solution that has worked for a <a href="http://epenguin.imalone.co.uk/2011/10/jack-for-audio-passthrough-on-fedora-15.html" target="_blank">couple of years</a> still works. If you want to get Pulse off the phone then shoot it (I don't recommend this approach if actually trying to get someone off the phone).</div>
<div style="text-align: justify;">
Assuming you use <a href="http://qjackctl.sourceforge.net/" target="_blank">QJackCtl</a> to control Jack (and if you don't, you should take a look, because it's very useful), just open Setup and go to the Options menu, in the 'Execute script on startup' section put:</div>
<div style="text-align: justify;">
<span style="font-family: "Courier New",Courier,monospace;">pulseaudio -k</span></div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
and in the 'Execute script after startup' section put:</div>
<div style="text-align: justify;">
<span style="font-family: "Courier New",Courier,monospace;">pactl load-module module-jack-source;pactl load-module module-jack-sink</span></div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
On a standard Fedora setup Pulse starts up again after it's been killed (our phone analogy maybe breaks down here). But in that time Jack has been able to get hold of the sound card. Once it has that it graciously listens out for anything Pulse might want to say and passes it on down the line.</div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-48346275302149395332012-11-01T00:01:00.002+00:002022-03-22T16:06:22.218+00:00Cooking the Jam<div style="text-align: justify;">
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Bubbling_Jam.jpg/256px-Bubbling_Jam.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Bubbling_Jam.jpg/256px-Bubbling_Jam.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">(<a href="http://commons.wikimedia.org/wiki/File:Bubbling_Jam.jpg" target="_blank">Wikimedia commons CC-BY-SA</a>)</td></tr>
</tbody></table>
Work on the <a href="http://fedoraproject.org/wiki/Fedora_jam" target="_blank">Fedora Jam</a> spin has been continuing over the summer, reaching a steady boil. What's new since my <a href="http://epenguin.imalone.co.uk/2012/06/getting-in-jam.html" target="_blank">last post</a>? Most of this has gone into packaging software...
<a name='more'></a>
Brendan Jones has been pushing an effort to get things in for review. These packages will be available for all Fedora users and as many as possible are going to make it into Fedora 18 (particularly if it keeps getting pushed back...). Some random highlights:<br />
<ul>
<li><a href="http://non.tuxfamily.org/" target="_blank">Non</a> is a suite of tools including a DAW and MIDI sequencer and advanced mixer that all integrate together via Jack.</li>
<li><a href="http://www.monocasual.com/giada/" target="_blank">Giada</a> another looper will join <a href="http://essej.net/sooperlooper/" target="_blank">SooperLooper</a></li>
<li><a href="http://drumkv1.sourceforge.net/drumkv1-index.html" target="_blank">drumkv1</a> a drum kit synthesizer released this week.</li>
<li><a href="http://piorekf.org/plug/" target="_blank">Plug</a>! Jonathan Underwood is packaging the Plug application for Fender Mustang amps. </li>
</ul>
...and many others which can be found in the <a href="https://bugzilla.redhat.com/show_bug.cgi?id=805236" target="_blank">Audio Spin Tracker</a> bugzilla.<br />
<br />
On top of this Jørn Lomax has been working on a <a href="https://bugzilla.redhat.com/show_bug.cgi?id=849026">Jam-control</a> app which will streamline enabling and disabling Jack and Pulseaudio when you need them. Jørn is also keeping the <a href="http://sheep-punchers.info/fedora-jam/" target="_blank">nightly compose</a> afloat, a tricky task before the spin receives official approval and can run on Fedora Project servers.<br />
<br />
It's not all sweetness yet. Theme-ing still needs a bit of tweaking; the focus is audio creation, but we want to take care of your eyes as well as your ears.<br />
More importantly Jack and Pulseaudio need to work smoothly. Work is going into this over the next few days. Some people's response to Pulseaudio is to rip it out, but as Pulse becomes more commonly the default for non-pro audio this is going to cause more problems. While it's an option for the Jam spin doing this would leave regular Fedora users out in the cold. But there's hope, Pulse-on-Jack works in Fedora 16, so it will be made to work in Fedora 18 too.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-AHcMOUZyPLk/UJG2kADreUI/AAAAAAAAARs/fbngquKMxzE/s1600/jam-splash.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://3.bp.blogspot.com/-AHcMOUZyPLk/UJG2kADreUI/AAAAAAAAARs/fbngquKMxzE/s1600/jam-splash.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">A splash of Jam...</td></tr>
</tbody></table>
The Jam is at a boil, now it just needs stirring.<br />
<ul>
</ul>
</div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-13613709412833857942012-09-24T00:14:00.001+01:002022-03-22T16:06:29.245+00:00Opus: teaching the world to sing<div style="text-align: justify;">
Earlier this month the IETF <a href="http://www.xiph.org/press/2012/rfc-6716/" target="_blank">accepted the Opus audio codec</a>. This might not seem like the most exciting news in the world and, unless you're really keen on technology standards or FOSS, it's not. But you might want to keep an eye on it.</div>
<a name='more'></a><div style="text-align: justify;">
A codec is the technology used to store or transmit information (code/decode), and the most famous one is probably MP3. MP3 kick-started the digital music revolution, but almost from the start was dogged by fights over patents and poor encoders. It got improved over the years, but was superseded by <a href="http://www.vorbis.com/" target="_blank">Vorbis</a>, AAC and others.</div>
<div style="text-align: justify;">
The problem with having lots of standards though is that there isn't a standard one and despite its flaws MP3 remains, nearly 20 years after its release, the most widely used codec. In approving Opus the IETF has managed to bring together several big players, including Microsoft and Google, and we can hope that support is going to be widespread.</div>
<div style="text-align: justify;">
So we'll probably be hearing more of Opus, will it change your life? It might. Opus started in two places - as an improvement to the technology used in Skype (SILK) and as the Xiph foundation's new low-latency music codec CELT (It's partly through the efforts of the Xiph and Mozilla foundations that Opus got the approval of IETF). Based on new technologies Opus beats almost every existing codec for quality at the same bitrate.</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://www.opus-codec.org/comparison/quality.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="237" src="http://www.opus-codec.org/comparison/quality.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">From Xiph http://www.opus-codec.org, license <a href="http://creativecommons.org/licenses/by/3.0/deed.en_US" target="_blank">CC-BY</a></td></tr>
</tbody></table>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Nice graphs like this are a bit suspect, but it's backed up by <a href="http://www.opus-codec.org/comparison/" target="_blank">testing</a> by several of the organisations involved in creating Opus. At high bitrates though you aren't going to see much difference in quality for music - all the top players are about the same.</div>
<div style="text-align: justify;">
The real advantage of Opus is low latency. Because audio codecs work in chunks there's a minimum wait-time between sound going in and out. Opus was designed from the start to be <u>really fast</u> and it has a lower latency than any music codec, and that means it can be used for real-time work.</div>
<div style="text-align: justify;">
In English: Opus can be used for <a href="http://en.wikipedia.org/wiki/Networked_music_performance" target="_blank">online performance and collaboration</a>. While it's still early days there is already an application called <a href="http://www.carot.de/soundjack/" target="_blank">SoundJack</a> based on Opus and even a <a href="http://www.virtualopenmic.org/about/" target="_blank">Virtual Open Mic Night</a> using it (disclaimer/warning, I haven't tried this yet...). Efforts like <a href="http://www.webrtc.org/" target="_blank">WebRTC</a> (real-time communications) are going to eventually make it even easier to get connected and jamming.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
Find out more at <a href="http://www.opus-codec.org/">www.opus-codec.org</a>.</div>
<div style="text-align: justify;">
Or, if your browser supports Opus you can try this sample from the Xiph foundation:
<audio controls="controls" src="http://repeater.xiph.org:8000/clock.opus">Bad luck if you don't see play controls here.</audio>
</div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-20366167350312798372012-08-11T16:01:00.001+01:002022-03-22T16:06:42.475+00:00Working on the railroad<div style="text-align: justify;">
Two pickup upgrade posts in a row might be a bit self-indulgent, but things get a bit more complex here, so I'm going to show how I've applied the ideas from <a href="http://epenguin.imalone.co.uk/2012/07/iron-in-blood.html">last time</a> to design the new setup. Last post I just replaced a pickup and added a simple coil tap, this time round we'll be adding a completely different wiring scheme. The trigger for all this is getting hold of a set of <a href="http://www.irongear.co.uk/irongear_019.htm" target="_blank">Jailhouse Rails</a></div>
<a name='more'></a><div style="text-align: justify;">
<br /></div>
<h3 style="text-align: justify;">
Pickups 101 again</h3>
<div class="separator" style="clear: both; text-align: justify;">
</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-yLQxOMrYLc0/UCWUyHIRnZI/AAAAAAAAAP4/IlCsokMN5xQ/s1600/singlecoil.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="86" src="http://4.bp.blogspot.com/-yLQxOMrYLc0/UCWUyHIRnZI/AAAAAAAAAP4/IlCsokMN5xQ/s320/singlecoil.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Single coil</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-QzvcpkbT4dI/UCWUxgij3kI/AAAAAAAAAP0/kT9qPg-3pGU/s1600/humbucker.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="164" src="http://1.bp.blogspot.com/-QzvcpkbT4dI/UCWUxgij3kI/AAAAAAAAAP0/kT9qPg-3pGU/s320/humbucker.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Humbucker</td></tr>
</tbody></table>
<div style="text-align: justify;">
Pickups pick up(!) the string vibration in a magnetic field and <a href="http://en.wikipedia.org/wiki/Michael_Faraday" target="_blank">turn it into an electrical signal</a> which goes to the amplifier. The two most common types are the single-coil and the humbucker (a doubled-up single coil). Single coils are known for a bright jangly sound; famously the Fender Telecaster and Stratocaster, and humbuckers for a darker sound; classically on the Les Paul.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
This rather <a href="http://www.moore.org.au/pick/04/04_lgen.htm" target="_blank">long and technical article</a> gives an explanation on how a lot of that difference arises from the way humbuckers are usually wired. What it comes down to is really the higher inductance pickups will sound darker and putting them in series (one-after another) produces what is effectively a higher inductance pickup. There are two ways to get a more single-coil like sound out of a humbucker, if you have a four-wire version: coil tap (basically use one coil) or wire in parallel. It isn't the whole story, for example the larger humbucker covers more of the strings and the coils are constructed differently, but it is an important part of it.</div>
<div style="text-align: justify;">
<br /></div>
<h3 style="text-align: justify;">
Go to jail, collect rails</h3>
<div style="text-align: justify;">
My goal here is to make my guitar a bit more versatile without changing it too much—no cutting holes in the scratch plate yet. Since the IronGear pickup in the bridge was pretty successful their <a href="http://www.irongear.co.uk/irongear_019.htm" target="_blank">Jailhouse Rails</a> were the obvious next step. These are humbuckers the size of a single coil pickup, which meant it could be swapped for the neck single coil on my Pacifica (if you want to spend more or get more choice, you might look at Seymour Duncan or DiMarzio, most boutique makers don't do them). It's a more square than a single-coil, so IronGear warn you might have to file out the space a bit, but on the Pacifica they just about squeezed through without that.</div>
<div style="text-align: justify;">
That could be it. The guitar has normal 3 pickup wiring with a 5 way switch and a coil-split for the bridge humbucker. I could just wire the rails straight in in place of the neck and, optionally, wire them up to the unused half of the switch for the coil-split. Except that now there's a humbucker in the neck and the bridge, that's the classic Les Paul configuration, if only there was some way to connect them together...</div>
<div style="text-align: justify;">
<br /></div>
<h3 style="text-align: justify;">
Rail Planner</h3>
<div style="text-align: justify;">
A 5-way switch, 3-pickup guitar (or, classic Stratocaster) switches from bridge to middle to neck pickup, with in-between positions bridge plus middle and middle plus neck.</div>
<div style="text-align: justify;">
A 3 position switch, 2-pickup guitar (classic LP) switches from bridge to bridge to neck pickup, with bridge plus neck in-between. In both cases 'plus' means in-parallel. The tone knob on this guitar can be replaced by one with a push-pull switch.</div>
<div style="text-align: justify;">
Destination: allow switching between the Stratocaster and LP in-between positions.</div>
<div style="text-align: justify;">
Via: We might as well allow a split-coil on the neck pickup too. </div>
<div style="text-align: justify;">
If I was willing to <a href="https://www.google.co.uk/search?q=super+seven+switching+guitar" target="_blank">cover the guitar in switches</a> then
I could allow all kinds of combinations, but I'm limiting myself to two
push-pulls. That rules out parallel/series humbucker switching,
since it needs both sides of a DPDT switch to do one humbucker.</div>
<div style="text-align: justify;">
It's also one reason I mentioned inductance above. High inductance pickups are usually thought of as high output, but if you put a high-inductance pickup in parallel with a lower inductance one the lower inductance pickup usually dominates the sound (because each pickup 'loads' the other). Ideally you have them matched. The least useful of the possible combinations is therefore switching the coil split individually, with both humbuckers engaged then it's better to have them both full or both coil-split.</div>
<div style="text-align: justify;">
That's the goal. If you've travelled on British trains you'll know things don't always go smoothly. The complication is single-coil humbucking.</div>
<div style="text-align: justify;">
<br /></div>
<h3 style="text-align: justify;">
Leaves on the line</h3>
<div style="text-align: justify;">
By single-coil humbucking I mean the combined pickup positions can be a humbucking combination to reduce noise. If you're wiring the pickups in phase (and I am) what you need is the combined pickups to have opposite magnetic polarity. The middle pickup is south (well, south on top), so when running split-coil it needs to combine with the bridge north or the neck north.</div>
<div style="text-align: justify;">
What happens when combining the bridge and neck pickups? North plus north? It's not critical, but it would be nice to be humbucking in this mode too. It turns out to be possible that in switching to bridge plus neck it's also possible to change which coil is used.</div>
<div style="text-align: justify;">
<br /></div>
<h3 style="text-align: justify;">
Rail network</h3>
<div style="text-align: justify;">
The final picture after all this worrying is quite simple. Add a push-pull switch that joins the bridge and neck hot leads together. Doing that means the bridge or neck positions on the 5-way lever become bridge plus neck, it also adds a bonus: the neck plus middle and bridge plus middle positions become neck plus middle plus bridge. One downside of doing this is that it would have been nice to have had the 'pointing' of the 5-way lever naturally swap to the 3-way pointing (neck plus bridge in the middle), that can be done, but all three pickups is a nice bonus and it also allows another trick.</div>
<div style="text-align: justify;">
The new push-pull switch is double-pole, which means that as well as joining neck to bridge it can also switch the coil-split for the neck pickup from earth to hot, this changes which coil is shorted by the coil-split switch and which one stays active. I've done this with the neck rather than the bridge pickup because there'll be less difference in the sound of the two coils at the neck rather than the bridge.</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-qFokoCS9Lro/UeheDKcCyuI/AAAAAAAAAc4/VZAGuO7v_04/s1600/wiring-jailhouse-correct.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="303" src="http://2.bp.blogspot.com/-qFokoCS9Lro/UeheDKcCyuI/AAAAAAAAAc4/VZAGuO7v_04/s1600/wiring-jailhouse-correct.jpg" width="320" /></a></div>
</td></tr>
<tr align="center"><td class="tr-caption">As in my last post '+' indicates the positive-on-lift wire<br />
for each pickup. To match the earth on the remaining<br />
stock
pickup 'hot' here is actually '-'.</td></tr>
</tbody></table>
<div style="text-align: justify;">
A diagram should make it clearer. Switch A coil-splits when pulled, switch B joins neck and bridge in parallel and changes the neck single coil from N to S.</div>
<h3 style="clear: left; text-align: justify;">
Making tracks</h3>
<div style="text-align: justify;">
"The bit with the pictures." You can draw as many neat schematics as you want, but those lines all translate into wires and solder. Here's another reason for keeping things simple, that silver backing on the scratch-plate is about the size of the Pacifica's electronics cavity. Start cramming more things in and you quickly run out of space.</div>
<div style="text-align: justify;">
</div>
<div style="text-align: justify;">
<br /></div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-nYZjzDths3M/UCZfq6V1PFI/AAAAAAAAAQY/inJOPq0StMY/s1600/DSCN1015-s.JPG" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://2.bp.blogspot.com/-nYZjzDths3M/UCZfq6V1PFI/AAAAAAAAAQY/inJOPq0StMY/s320/DSCN1015-s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Converting neat wiring diagrams<br />
to messy wire layouts</td></tr>
</tbody></table>
<div style="text-align: justify;">
One thing that's tricky is those 'earth points' that get soldered onto the back of pots. It's good to have a solid one with all the earths coming to a single point as it cuts down noise. However a massive blob of solder on the back of a metal potentiometer can be very hard to melt if you want to work on it later. The best solution is a copper tab soldered to the back of the pot, which you solder the other wires onto, not having one to hand I've used a double thickness of tinned hookup wire.</div>
<div style="text-align: justify;">
<br /></div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-goRb8ym2iVw/UCZfqLTk_JI/AAAAAAAAAQQ/LMgQLTfmNO8/s1600/DSCN1012-s.JPG" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://3.bp.blogspot.com/-goRb8ym2iVw/UCZfqLTk_JI/AAAAAAAAAQQ/LMgQLTfmNO8/s320/DSCN1012-s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Earthing onto a doubled end of hookup wire,<br />
bottom right.</td></tr>
</tbody></table>
<div style="clear: right; text-align: justify;">
The nice orange capacitor is a Sprague 22nF tone capacitor. I took the opportunity to replace the standard one in the Pacifica 112, though I found out that was already a 22nF, while diagrams for the
112J show a 47nF. The old potentiometer turns out to have been a 250k
log pot rather than the linear one I was expecting, my push-pull
replacement is a 250k linear pot. The log pot was a better choice, but I
can live with the linear one for the moment.</div>
<h3 style="clear: both; text-align: justify;">
All aboard</h3>
<div style="text-align: justify;">
With everything squeezed back into place the guitar doesn't look much different. Maybe the rails don't quite match the vintage look of the rest of the finishing (and maybe I'm harbouring cosmetic plans about that), but the sound though is very nice. The Jailhouse Rails pair well with the Hot Slag and deliver a sound with a solid bass punch, but that's still articulate and lets highs come through. Switching on the coil-split in that mode gets an even brighter sound, while putting in the mid as well warms things a little. On their own the rails work nicely, with a thick but clear sound on full and brightening up again in coil-split.<br />
The different noise cancelling modes all work turned up loud, while there's very little noise overall, despite all the cables and unorthodox earth.</div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" id="finished" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://4.bp.blogspot.com/-3ndch17ofow/UCZfrs4C1-I/AAAAAAAAAQc/lPfPn19UToY/s1600/DSCN1239-s.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" height="300" src="http://4.bp.blogspot.com/-3ndch17ofow/UCZfrs4C1-I/AAAAAAAAAQc/lPfPn19UToY/s400/DSCN1239-s.JPG" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Gratuitous gear shot.</td></tr>
</tbody></table>
<div style="text-align: justify;">
That's probably enough gear posts for a while, back to some interesting developments for music on Linux shortly.<br />
<h3>
Update 18 July 2013</h3>
The wiring diagram was slightly wrong, the neck half of switch A connects when pulled, now fixed. (You can see this in the first wiring picture.)</div>
justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com2tag:blogger.com,1999:blog-3637061929524336435.post-58576564050691967962012-07-02T01:59:00.001+01:002022-03-22T16:06:47.616+00:00Iron in the Blood<div style="text-align: justify;">
The
pickups are the heart of an electric guitar. People debate about how
the sound is affected by string gauge, bridge, body woods, necks,
fretboards, even finishes. There's probably someone prepared to tell you
inlays make a difference. But no-one questions the pick-ups'
contribution. All the other factors change the sound in different
(sometimes imaginary) ways, but it's the pickups that pump it out.
Fortunately changing them is much easier than a heart transplant.</div>
<div style="text-align: justify;">
<a name='more'></a><div style="text-align: justify;">
The Yamaha Pacifica 112 is a solid entry-level electric: an easy neck to
play, a stratocaster-like three pickups configuration which gives a
range of sounds and solidly constructed. A humbucking bridge pickup
provides a bit of extra firepower for heavier rock and blues sounds.
When Yamaha updated the guitar around 2010 they added a few things, including making it even more versatile by adding a coil-tap to the bridge pickup (switch between single coil and humbucker). Mine was made before this upgrade, which led to the opportunity for some DIY.</div>
<div style="text-align: justify;">
Changing pickups is not very difficult, but I'm writing about it because there are some things, especially if doing it for the first time, which aren't really mentioned out there on the web. Of course you might know all this already and just <a href="http://ibmalone.blogspot.com/2012/07/iron-in-blood.html#operation" target="">skip straight to the pictures</a>.<br />
<h3>
Picking it up</h3>
The very basic overview on guitar pickups: it's a coil of wire around a magnet. The vibration of the string above it changes the magnetic field in the coil and induces a voltage in the coil (thank you <a href="http://en.wikipedia.org/wiki/Michael_Faraday" target="_blank">Michael Faraday</a>). This coil of wire obviously has two ends, there is also an earth wire that connects to the metal body of the pickup and shields the cable from interference. That's a total of three wires. In stock pickups the earth is often connected to one of the coil wires, bringing it back down to two. A humbucker is made of two pickups in one package, how many wires does it have? Somewhere between two and four plus earth (you might call that five...).<br />
<h3>
Getting hot</h3>
This is important. Take a piece of string and wind it round a pencil. Now trace from one end of the string to the other. You are either going clockwise or anti-clockwise, depending how you wound it and which end of the pencil you're looking at. Similarly for pickups, there are two ways round those two wires can go. This might not matter except if you want to have two or more pickups connected at the same time - the 'intermediate' positions in most guitar switching. You need all the valves of your heart pumping the same way. If you buy a pickup it will probably come with a diagram telling you which way is 'hot', but all 'hot' actually means is the end that's not connected to earth and different manufacturers have different ideas about which end that should be. Fortunately there is a way to find out. You will need:<br />
<ol>
<li>A steel screwdriver (not a magnetised one), or spanner, or piece of cutlery, or small decorative figurine. Steel is the thing, aluminium can't help us here.</li>
<li>A multimeter, analogue is good, but digital will do.</li>
</ol>
And all you do is this:<br />
<ol>
<li><b>Gently</b> touch the screwdriver onto the pickup pole pieces. If you really are using an oddly shaped implement use a blunt area.</li>
<li>Connect the multimeter to the coil wires and set it to <b>DC</b> voltage, order of 20mV (millivolts) scale.</li>
<li>Quickly lift the screwdriver off the pickup, while watching the multimeter and without stabbing anyone (or yourself).</li>
</ol>
If the multimeter goes positive when you lift the screwdriver off then the positive multimeter probe is connected to what we'll call the + wire of the coil (this is easier to see on an analogue meter). If it goes negative then the negative probe is connected to the + wire. Calling it the + wire doesn't necessarily agree with what anyone else will call it, just make a note of which one it is.<br />
You can do the same thing to your guitar without opening it up, just plug in a cable and connect the multimeter to the other end. The tip is 'hot' and the sleeve is 'earth', either one could be the '+' end (e.g. supposedly Fender and Gibson are the opposite way around). Check the reading changes if you swap the probes round—if your multimeter is in AC mode it'll tell you + either way.<br />
<h3>
Just a phase (or two, or three)</h3>
I've avoided the word phase, because it can legitimately mean several things and it's used wrongly to mean even more. I'm going to keep avoiding it and try to say this in a way that makes it clear what's going on. There are two things to worry about when combining pick-ups:<br />
<ol>
<li>They are pushing in the same direction. That's the '+' thing above. Some people do actually like the sound of having them push the opposite direction (they don't entirely cancel), but it's much thinner (sometimes called 'nasal').</li>
<li>Noise cancellation (for single coils). Which end is '+' depends on the direction of the magnet (or pencil) and the direction of winding. But for background noise (e.g. mains hum) only the direction of winding matters. So if you have two pickups with magnets the opposite way up and you join their '+' together (in parallel), they will have opposite noise and it largely cancels. This is how a humbucker works. You might see the term 'RWRP', which means reverse wound reverse polarity and is often used for strat mid pickups to get that effect. However 'RW' really just comes down to what way round you connect the wires: what you're really looking for is the magnets the other way round. Easy way to tell? If the pickups push apart when head-to-head they have the same magnetic polarity, if they attract they're opposite. For a set of strat single-coil pickups the middle one should attract the other when two head-to-head. (Don't try and force them together if they push apart, they don't like it).</li>
</ol>
All this is great, but if your new pickup doesn't have a separate earth wire you have to choose between having it the right way round to match the other pickups in your guitar and having it the right way round to earth properly. Fortunately after-market pickups should normally have a separate earth. If you're adding a new pick-up regard 'hot' for the pickup as whatever end matches 'hot' for the guitar and the earth connections for the stock pickups will already be okay.<br />
If your pickup doesn't have opposite magnetic polarity to the ones it will combine with then it's probably better to make sure the '+' match. Unless you really do want that nasal sound or to play very high gain with mixed positions.<br />
<h3 id="operation">
Cast Iron</h3>
Putting it into practice. We have one Yamaha Pacifica pre-2010. To add a coil split switch it's necessary to get a new bridge humbucker, because the existing one has only two wires and a coil split needs access to the connection between the two halves. You can spend a lot on pickups and I didn't really want to spend more than the re-sale value of the guitar. You can also spend very little and get rubbish, which wouldn't have been much of an upgrade.<br />
<a href="http://2.bp.blogspot.com/-jiOGxvKdKTk/T_C2-95acoI/AAAAAAAAALg/r70nbX6Rijo/s1600/DSCN8156_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="http://2.bp.blogspot.com/-jiOGxvKdKTk/T_C2-95acoI/AAAAAAAAALg/r70nbX6Rijo/s320/DSCN8156_s.JPG" width="320" /></a>After a bit of searching around I found <a href="http://www.irongear.co.uk/" target="_blank">IronGear</a> who are a British brand making affordable pickups overseas and getting very good reviews for them. Their <a href="http://www.irongear.co.uk/irongear_018.htm" target="_blank">Hot Slag</a> is a bit higher output than the pickup it's replacing, but the idea is that in single-coil mode it should pair up with the Pacifica's middle pickup, which is fairly high impedance too. The <a href="http://www.irongear.co.uk/irongear_022.htm" target="_blank">Rolling Mill</a> is more vintage-voiced and classic rock than the hot slag which heads off into hard rock and metal territory. The Steam Hammer heads off even further down that road, but the hot slag seemed the one to go for. The pickups and other bits and pieces that were needed (practical: a new volume control with a switch, extra wire, new control knobs; decorative: some new black trim) were all bought from <a href="http://www.axetec.co.uk/index.htm" target="_blank">Axetec</a> who were very easy to deal with (IronGear is their brand).<br />
<h3>
Making the cut</h3>
I've been telling this story backwards so far, I knew I needed a new pickup because I opened the guitar up first, I know about checking the '+' rather than relying on manufacturer's 'hot' label because I started by wiring things up the wrong way around. From here on the story goes forwards. Here's the inside of the pre-2010 Pacifica.<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-aMp_aTHFtzg/T_C3DOjx13I/AAAAAAAAALw/5WESgZtQDwM/s1600/DSCN8270_s.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="http://1.bp.blogspot.com/-aMp_aTHFtzg/T_C3DOjx13I/AAAAAAAAALw/5WESgZtQDwM/s320/DSCN8270_s.JPG" width="320" /></a></div>
<br />
All the stock pickups are 12kΩ (most after-market ones have different bridge, middle and neck variants), all have only two wires. The voltage pot is 500kΩ log (what you might expect for the humbucker in the bridge) and the tone pot is 250kΩ with a 22μF capacitor. The routing for the pickups is a 'bath-tub' type and the routing for circuitry is fairly (39mm) deep.<br />
<h3>
(Single) Bypass</h3>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: justify;"><a href="http://4.bp.blogspot.com/-ZfSsaZhTOKc/T-80Hhh2V7I/AAAAAAAAAKw/rbteMt8bPAs/s1600/wiring2.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://4.bp.blogspot.com/-ZfSsaZhTOKc/T-80Hhh2V7I/AAAAAAAAAKw/rbteMt8bPAs/s320/wiring2.jpg" width="276" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Wiring for split-coil,'+' is marked for each<br />
coil, and it's connected to ground to match<br />
the original pickups. Arrows show the hot<br />
leads going to the selector switch.</td></tr>
</tbody></table>
My main aim here is to add the coil tap switch. Like the new model Pacifica this is going to be a push-pull switch on the volume knob. That means a new volume pot and some grippier knobs (LP-style speed knobs). The switch is wired so when it's pulled out it shorts out one of the humbucker coils. Which one? This is the reason for my earlier rambling: I want the remaining coil to have the opposite polarity to the existing middle pickup. For me that means the black side of the zebra pickup and the black-white pair of wires. The final wiring is on the right.<br />
The Hot Slag is connected backwards compared to IronGear's suggestion, because the other pickups are that way round, the split-coil switch shorts the green to red turning off the 'S' pickup coil, leaving the 'N' one.<br />
If I'd wanted the single coil the closest one to the bridge the thing to do would be turn the pickup around. <br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-zEO2b1_Z-ys/T_Buf-aTEdI/AAAAAAAAALE/IUDx4-dl7EI/s1600/DSCN8272_s.JPG" style="margin-left: auto; margin-right: auto;"><img border="0" height="239" src="http://1.bp.blogspot.com/-zEO2b1_Z-ys/T_Buf-aTEdI/AAAAAAAAALE/IUDx4-dl7EI/s320/DSCN8272_s.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Pacifica scratchplate with the IronGear fitted.<br />
If you look too closely you'll notice the new pickup<br />
is wired the wrong way around at this point.</td><td class="tr-caption" style="text-align: center;"><br /></td></tr>
</tbody></table>
<h3 style="clear: both;">
Dressing right
</h3>
<a href="http://3.bp.blogspot.com/-BhlnTSEYY2s/T_C3GJWUeEI/AAAAAAAAAMA/7SdDjbvvS0k/s1600/DSCN8289_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/-BhlnTSEYY2s/T_C3GJWUeEI/AAAAAAAAAMA/7SdDjbvvS0k/s320/DSCN8289_s.JPG" width="240" /></a>To use a push-pull switch you have to be able to pull it, so a new volume knob with good grip is needed. One symptom of the Hot Slag's heavier rock leaning is that it doesn't come with white bobbins. Well, the whole lot may as well match, so it's time to make some decorative changes. Fortunately single-coil covers can be changed easily (and fortunately someone pointed this out to me).<br />
<h3 style="clear: both;">
Iron(Gear) in the blood</h3>
Before and after, black speed knobs with grips, black selector knob
and black pickup covers. With a hint of yellow. Maybe I should start
calling it Tux...<br />
(Maybe not.)<br />
<div style="clear: both;">
<br /></div>
<a href="http://3.bp.blogspot.com/--1UoNpt9ogA/T_C3HaUkEQI/AAAAAAAAAMI/Emp472zUkuU/s1600/DSCN8293_s.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://3.bp.blogspot.com/--1UoNpt9ogA/T_C3HaUkEQI/AAAAAAAAAMI/Emp472zUkuU/s320/DSCN8293_s.JPG" width="240" /></a></div>
<a href="http://1.bp.blogspot.com/-dsBAiihsqIk/T_C3A0l-MsI/AAAAAAAAALo/T8nifH86FfE/s1600/DSCN8162_s.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/-dsBAiihsqIk/T_C3A0l-MsI/AAAAAAAAALo/T8nifH86FfE/s320/DSCN8162_s.JPG" width="240" /></a><br />
<br /></div>
<h3 style="clear: both;">
Post-op</h3>
<div style="clear: both;">
The last thing to do is set the pickup height, see <a href="http://www.ratcliffe.co.za/articles/pickupheight.shtml%20" target="_blank">Alan Ratcliffe's article</a> or <a href="http://home.roadrunner.com/%7Enils/BasicGuitarSetup.htm#pickup" target="_blank">Nils on guitar setup</a>. I wont claim to be expert at reviewing pickups, but the Hot Slag sounds good. It's a bit higher output than the standard one, but splitting it dials it back and gives a brighter sound which will also mix nicely with the middle pickup. The only downside is that now I want to try changing all the others. <span style="font-size: x-small;">Sound clips to follow, <span style="font-size: xx-small;">maybe</span>?</span></div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com1tag:blogger.com,1999:blog-3637061929524336435.post-31899153364505886542012-06-30T05:04:00.001+01:002022-03-22T16:06:53.203+00:00Getting in a Jam<div style="text-align: justify;">
Back in April <a href="http://fedoraproject.org/wiki/User:Jvlomax" target="_blank">Jørn Lomax</a> was awarded a Google Summer of Code (<a href="http://code.google.com/soc/" target="_blank">GSOC</a>) place to work on the (as it was) Fedora Audio Spin. While there have long been people working on music and audio in Fedora, a GSOC place means there is someone with time (and deadlines) to focus on getting things done.</div>
<div style="text-align: justify;">
The project is now burning along in 16/16 time as <b><a href="http://fedoraproject.org/wiki/Fedora_jam" target="_blank">Fedora Jam</a></b>.</div>
<a name='more'></a><div style="text-align: justify;">
For the uninitiated a 'spin' is a customized Linux distribution aimed at a particular goal without including the kitchen sink (you can always download a sink later if you want). They can often be run live (without installing) as well as installed to give you a system optimised for, in this case, making music.</div>
<div style="text-align: justify;">
As well as making sure all the programs you might need are there a spin can also be crafted so it's easy to set up and things you need, like real time audio, work as well as possible.</div>
<div style="text-align: justify;">
What will be in it? This is still being worked out, but you can expect digital audio workstations like <a href="http://ardour.org/" target="_blank">Ardour</a>, scoring and music writing tools like <a href="http://lilypond.org/" target="_blank">Lilypond</a>, lots of audio plugins, and instrument and synth tools like <a href="http://www.hydrogen-music.org/hcms/" target="_blank">Hydrogen</a> and <a href="http://guitarix.sourceforge.net/" target="_blank">Guitarix</a> (the guitar angle). With some quiet orchestration to make sure it all works in harmony.</div>
<div style="text-align: justify;">
Fedora Jam is being aimed to arrive with <a href="http://fedoraproject.org/wiki/Releases/18/Schedule" target="_blank">Fedora 18, t</a>o find out what you can do in Fedora <b>right now</b>, have a look at the <a href="http://docs.fedoraproject.org/en-US/Fedora/16/html/Musicians_Guide/index.html" target="_blank">Fedora Musicians Guide</a>. You can keep track of progress (and take part!) at the <a href="http://fedoraproject.org/wiki/Audio_creation_spin_development" target="_blank">spin development page</a> or get involved in the <a href="https://admin.fedoraproject.org/mailman/listinfo/music" target="_blank">mailing list</a>.</div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-74475868288304133002012-05-07T02:06:00.001+01:002022-03-22T16:07:01.056+00:00Why read music - an off-beat look<a href="http://www.guitarnoise.com/lesson/tyranny-of-tablature/" target="_blank"></a>
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<a href="http://epenguin.imalone.co.uk/2012/05/why-read-music-off-beat-look.html#more" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="205" src="http://1.bp.blogspot.com/-jAgm32uwrsQ/T6cZqBoS1JI/AAAAAAAAAKI/djJKLnTaFQQ/s320/DSCN8068-s.jpg" width="320" /></a></div>
A post which has no Linux, not much guitar, and attempts to persuade you to do something pretty boring.</div>
<a name='more'></a><br />
<br />
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<br /></div>
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Last month I read a book which set me thinking about what happens when you learn to read music. One discussion that often comes up online, among guitarists at least (who also have the simpler tablature), is whether you should learn to read music. This is a
question that often gets asked, not infrequently with the subtext
'clearly my natural musical genius means skipping this tedious step
wont prevent me becoming a rock god'. I write this as someone who
knows what the dots mean, but still has to figure out the key signature or
an individual chord.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
The book in question is <a href="http://en.wikipedia.org/wiki/Maryanne_Wolf">Maryanne Wolf's</a> <a href="http://www.amazon.co.uk/Proust-Squid-Story-Science-Reading/dp/1848310307/ref=sr_1_1?ie=UTF8&qid=1335566145&sr=8-1">Proust and the Squid</a>. Dr Wolf is a researcher in the neurological
basis of reading, mainly the development of reading in children.
Proust and the Squid (one of the book's let-downs is it features
little Proust and fewer squid) discusses the development of writing
systems in history, the different demands different systems make of
the brain (e.g. Chinese vs German vs English), how children learn to
read and reading deficits (dyslexia). There are three stages she
describes in early (pre-expert) reading (in literate societies it's
assumed):</div>
<div style="margin-bottom: 0cm; text-align: justify;">
</div>
<ul>
<li><b>Pre-reader</b> For the first five
years of life children learn their language. They acquire thousands
of words and grammatical rules. This process will continue through
and be reinforced by the following stages.</li>
<li><b>Novice reader</b> A lot happens
at this stage, learning letters correspond to sounds, correspondingly
that words are made up of sounds. Recognising orthographic patterns
(in English, things like 'eng', 'th', 'sh' and so on). Understanding
different meanings of words. Three areas of the brain are involved,
the visual system, semantic (meanings) and language comprehension
areas, and parts of the frontal lobes involved in memory and
speech.</li>
<li><b>Decoding</b> This is a
semi-fluent stage where reading becomes smoother. In English this
involves recognising larger patterns (e.g. how 'ea' is different in
dear, bear, reap, head) and morphemes-the parts (stems, prefixes,
suffixes) of words- for example 'sing' and -s, -er in sing-s and
sing-er (or guitar, guitar-s, guitar-ist).</li>
</ul>
<div style="margin-bottom: 0cm; text-align: justify;">
Why am I bothering with all this? The point is that as those skills
improve the brain becomes more efficient at the basics. The
activation regions in the visual and recognition areas actually
become smaller in fluent readers as the brain begins to get better at
those tasks until all the above things happen automatically. What
starts to happen then is the interesting bit.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
Firstly 'automatic' by itself is pretty
amazing, a fluent reader looking at a word is prompted with its
meaning(s) without having to think about it. As far as Wolf is
concerned this is key to reading: freeing the reader up to think
about what they're reading rather than how (when you're playing
tennis you don't want to be concentrating on breathing in and out).</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
Further, though the visual and
association areas are less activated as they work less hard,
different regions of the brain start to activate. An 'expert' reader
(basically someone capable of reading a novel) will involve different
parts of their brain including large parts of the left and right
language areas and deep-seated areas related to emotion.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
Lastly, a very interesting nugget that
takes us right back to the start... a study in rural Portugal
comparing literate and illiterate people found only the literate
individuals were able to identify phonemes in speech (e.g. the 'b' in
'birth') and the illiterate subjects had difficulty repeating
nonsense words, rather saying similar real words instead.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
So, to make some unfounded speculations
about what this might mean for learning to read music. Reading is not
a separate 'module' that you just plug into the input to language or
auditory centres, it's a network process that uses those regions as
an integral part and in practicing reading you exercise them. In the
early stages it does focus on learning to recognise symbols and how
they combine together and correspond to sounds (or in the case of
writing systems like Chinese, words, and those use some different
brain regions), but as fluency improves the visual and recognition
side fades into the background and many other regions start to get
more attention. During that learning process the learner is also
exposed to many different words, usages and idioms and these all get
taken on board. Automaticity also means the rest of the brain gets
more time to process incoming information. Finally the practice and
the exposure to material during learning contribute to improving the
ability to understand what is read.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
It's not essential. For thousands of
years people spoke their own languages fluently without being
literate. We have some superstar musicians who admit they can't read
music (did someone say Paul?), the same way there were illiterate poets
(Homer, there may still be some, but literacy is so widespread now
it's less likely). And stage 1. above is learning thousands of words
before learning a single letter (Wolf also says children who get
exposed to more spoken language will have an easier time learning to
read).</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm; text-align: justify;">
Before recording, and particularly
digital technology, written music was the only way for a learner to
'slow down' music, particularly to understand rhythm and see its
parts the same way alphabetic and syllabic systems do for words. And,
like for reading, new technologies might change things about the way
we communicate and learn. But, if if what's true about reading
language is true for music, I think the two things to take away are:
knowing music is a good foundation for learning to read it, reading
music will help you understand it.</div>
<div style="margin-bottom: 0cm; text-align: justify;">
<br /></div>
<div style="margin-bottom: 0cm;">
Some practical aids:</div>
<ul>
<li><a href="http://www.amazon.co.uk/The-Right-Way-Read-Music/dp/0716022001/ref=sr_1_1?s=books&ie=UTF8&qid=1336351514&sr=1-1" target="_blank">The Right Way Read Music (amazon)</a> a good guide to the dashes and dots and basic theory (thanks to Alan Green at <a href="http://www.guitarnoise.com/" target="_blank">Guitar Noise</a> for recommending it).</li>
<li>Mel Bay's modern guitar method (<a href="http://www.amazon.co.uk/Mel-Bays-Modern-Guitar-Method/dp/0871663546/ref=sr_1_1?s=books&ie=UTF8&qid=1336351473&sr=1-1" target="_blank">Book 1 at amazon</a>), uses only standard notation. The equivalent <a href="http://www.amazon.co.uk/Leonard-Guitar-Method-Complete-Version/dp/0634047019" target="_blank">Hal Leonard books</a> provide tablature and standard notation for some exercises and standard-notation only for others, maybe an easier compromise.</li>
<li>Ear training (<a href="http://epenguin.imalone.co.uk/2012/01/ear-training-phrase-training-in-fedora.html" target="_blank">list of resources</a>), after all you need to train your recognition of the music to match what's on the page.</li>
<li>The Guitar Noise '<a href="http://www.guitarnoise.com/topic/theory/" target="_blank">Theory without tears</a>' lessons, including Nick Minnion's lessons (<a href="http://www.guitarnoise.com/lesson/tyranny-of-tablature/" target="_blank">part 1</a>, <a href="http://www.guitarnoise.com/lesson/making-musical-milestones/" target="_blank">part 2</a>, <a href="http://www.guitarnoise.com/lesson/some-practical-pointers/" target="_blank">part 3</a>).</li>
<li>Time. The more you put in the easier it will get and the more it will connect with everything else. At least, that's what I'm telling myself...</li>
</ul>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-71236337023233656752012-04-02T01:42:00.031+01:002022-03-22T16:08:02.678+00:00Breaking in the Fender Mustang<div style="text-align: justify;">
In 2010 Fender came out with the <a href="http://www.fender.com/en-GB/products/mustang/" target="_blank">Mustang range of amplifiers</a>. These are incredibly cheap modelling amplifiers starting at 20Watts (or the 7W battery model), going up to a 150Watt head and this year introducing a floor-unit based on the same technology. I ended up getting one of these a little while ago while looking for something that was more of an all-rounder than my last practice amp.</div>
<a name='more'></a><br />
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
As always, Linux Journal has already managed to do a great <a href="http://www.linuxjournal.com/content/plug-and-fender-mustang" target="_blank">article on the Mustang</a>, but I thought it would be worth sharing my experiences (the amp itself, Fedora and Windows) and a couple of tricks they missed. Of course if you know what Fuse an Plug are already and just want to get to the technical stuff then <a href="http://www.blogger.com/post-edit.g?blogID=3637061929524336435&postID=7123633702323365675#jacksetup">jump ahead</a>.<br />
<br /></div>
<h3 style="text-align: justify;">
Meet the Mustang</h3>
<div style="text-align: justify;">
<a href="http://3.bp.blogspot.com/-b9aefFIleV8/T3jrCZ96-SI/AAAAAAAAAIc/H1u0fQxA-08/s1600/frontview.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="301" src="http://3.bp.blogspot.com/-b9aefFIleV8/T3jrCZ96-SI/AAAAAAAAAIc/H1u0fQxA-08/s320/frontview.JPG" width="320" /></a>Since the Mustang has been around for nearly 2 years lots of other people have written about it. Mine is the small one, a Mustang I for home practice. From model III upwards there are more controls on the panel and a lot more kick. In the shop it came down to this or a Vox Vt40+, if you're wondering why I was comparing the Fender with a Vox twice as powerful, it's because they didn't have the smaller Vt20+.</div>
<div style="text-align: justify;">
If they had done I might not be writing this article. Both sounded fine, maybe it was a bit easier to get the Vox into drive, but for both it was also clear that it would take more time to get the best out of them, and it's the approach to controls that really sets them apart. Ignoring tone and volume knobs, the Mustang's amp and effects section is less easily configured than the Vox's. There is one dial controlling presets (tied to amplifier models), one dial selecting modulation effects and one dial selecting delay and reverb. Getting a sound amounts to spinning through the presets and finding one you like.</div>
<div style="text-align: justify;">
The Vox on the other hand controls everything separately and it's a lot more obvious how you might do things like adjust effect levels. I came away with the Mustang only because the Vox couldn't be reduced to a volume I thought was usable at home, but the Mustang definitely had some good sounds in it.</div>
<div style="text-align: justify;">
<div class="separator" style="clear: both; text-align: center;">
<a href="http://4.bp.blogspot.com/-h02IQEodQSo/T3juNxXZ35I/AAAAAAAAAIs/MR3cA2QtH8Y/s1600/panel.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="143" src="http://4.bp.blogspot.com/-h02IQEodQSo/T3juNxXZ35I/AAAAAAAAAIs/MR3cA2QtH8Y/s320/panel.JPG" width="320" /></a></div>
The Mustang is fun though; all you need to do with it is turn it on, find the amp model you want by spinning through the presets and then get playing. Actually, a lot of things can be tweaked on the panel once you've read the manual, but not all (at least for the I & II models).<br />
<br /></div>
<h3 style="text-align: justify;">
Horse whispering</h3>
<div style="text-align: justify;">
One of the most noticeable things about this amp is the USB connectivity (because it's in big letters on the box). There's no official linux software, but, thanks to one Linux developer and the use of USB Audio, everything you can do in Windows you can do in Linux. What can you do? The USB interface provides both more detailed control of the amp settings and a direct digital recording interface. With the settings control you can adjust all the settings for the individual effects, meaning you have as much control over the Mustang I as the Mustang V (there are still differences in the hardware), and you can do things to the effect order and application that are impossible through the panel.<br />
<br /></div>
<h3 style="text-align: justify;">
Direct recording</h3>
<div style="text-align: justify;">
There is a dual purpose headphone/line out jack, so you could just use that (see the <a href="http://ibmalone.blogspot.com/2011/10/jack-for-audio-passthrough-on-fedora-15.html" target="_blank">Jack setup</a> and <a href="http://ibmalone.blogspot.com/2011/11/let-right-noise-in.html" target="_blank">let the right noise in</a> posts), but using the digital connection avoids any interference and the possibility of ground loops arising between the computer and the amp, plus you can hear exactly what you're playing while recording, sounds like a good idea. To get this working in Fedora just plug it in. The Mustang will appear as a recording source in the sound settings, note that the amplifier wont act as a speaker - you can't play back through it.</div>
<div style="text-align: justify;">
One thing I've noticed about this though, in newer firmware there is a 'USB gain' setting. This is recorded in the presets and set to the lowest possible in most. If you find that the recording level is too low you can adjust it by holding down the 'exit' button on the amp while turning the 'volume' button. This wont change the normal volume setting, though the amp does take the common 'last remembered position' approach, so if you adjust the actual volume afterwards then that jumps to whatever the dial was left at.<br />
<br /></div>
<h3 id="jacksetup" style="text-align: justify;">
Jacking in</h3>
<div style="text-align: justify;">
Of course if you want to use Ardour or Guitarix you're probably going to want to use Jack. Jack is most commonly setup to use one device, but you'll likely want to split it across the Mustang as input and your soundcard as output. If you've read <a href="http://ibmalone.blogspot.com/2011/10/jack-for-audio-passthrough-on-fedora-15.html" target="_blank">Jack for audio passthrough</a> then this will look familiar:</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-Ti9DoEieV-4/T3jvk3Je00I/AAAAAAAAAJY/0ldC2iKFQvY/s1600/jack-setup-s.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="82" src="http://2.bp.blogspot.com/-Ti9DoEieV-4/T3jvk3Je00I/AAAAAAAAAJY/0ldC2iKFQvY/s320/jack-setup-s.jpg" width="320" /></a></div>
<ul>
<li>Install <b>qjackctl</b> and <b>pulseaudio-module-jack</b> from the Add/Remove software menu</li>
<li>Start qjacktl (from the sound and video menu) hit the stop button if Jack has started.</li>
<li>Open setup and go to options, check that</li>
<li>Execute script after startup has "pactl load-module module-jack-source;pactl load-module module-jack-sink"</li>
<li>Execute script on startup has "pulseaudio -k"</li>
</ul>
Now the new part:<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-YdGRnaxGeUA/T3jvjfe71oI/AAAAAAAAAJM/QU0YKcUpesw/s1600/jack-preset-dropdown-sf.jpg" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="185" src="http://2.bp.blogspot.com/-YdGRnaxGeUA/T3jvjfe71oI/AAAAAAAAAJM/QU0YKcUpesw/s200/jack-preset-dropdown-sf.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Storing Jack presets</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ADnFhoGsA3A/T3jvkJuScdI/AAAAAAAAAJQ/lxdc578Esa4/s1600/jack-select-io-devices-s.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="187" src="http://1.bp.blogspot.com/-ADnFhoGsA3A/T3jvkJuScdI/AAAAAAAAAJQ/lxdc578Esa4/s200/jack-select-io-devices-s.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Separate input and output settings</td></tr>
</tbody></table>
<br />
<ul>
<li>Go back to Settings, if you want to keep your current setup then name and save it.</li>
<li>Click the right arrow next to Input Device, select the Mustang<br />
<br />
<br />
</li>
<li>Click the right arrow next to Output Device, select your soundcard</li>
<li>Check the rate is 44100Hz(this is the Mustang's output rate)</li>
<li>Name and save this as a new preset, click okay.</li>
<li>Start Jack.</li>
</ul>
<div style="text-align: justify;">
That's it, you can try out pass-through by opening the connections window and connecting system in to system out, this will now send the Mustang signal direct to your soundcard. Of course if you're monitoring through headphones or computer speakers then you might not want the amp speaker going, just turn the master volume all the way down, this doesn't affect the recorded sound and isn't stored in any of the amplifier presets.</div>
<div style="text-align: justify;">
Those devices in Jack can change if you connect or disconnect other sound sources (a webcam for example), if you want to be sure they will always connect correctly then you can get the names by opening a console window and doing:</div>
<div style="font-family: "Courier New", Courier, monospace; text-align: justify;">
cat /proc/asound/cards</div>
<div style="text-align: justify;">
You can use the names (in square brackets) as hw:Name, (e.g. hw:Amplifier) in the input and output names in Jack.<br />
<br /></div>
<h3 style="text-align: justify;">
Plugging in</h3>
<div style="text-align: justify;">
Fender provide their Fuse software to control amp settings, this requires Silverlight and getting it running in Wine is unlikely (actually, getting it running in Windows proved tricky). Fortunately a programmer called Piorekf has taken the trouble to document the commands sent to the amp and write a Linux equivalent: <a href="http://piorekf.org/plug/" target="_blank">Plug</a> and, while you can compile it from source if that's your thing, <a href="https://build.opensuse.org/package/show?package=plug&project=home%3AetamPL%3Apiorekf" target="_blank">it's already been packaged for Fedora here</a>. For the moment there's a fix needed to give you permissions to access the amp:</div>
<ul>
<li>Put this in the file /etc/udev/rules.d/50-mustang.rules<br />
<span style="font-family: "Courier New",Courier,monospace;">SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", \</span><br style="font-family: "Courier New", Courier, monospace;" /><span style="font-family: "Courier New",Courier,monospace;"> ATTRS{idVendor}=="1ed8", ATTRS{idProduct}=="000[456]", \</span><br style="font-family: "Courier New", Courier, monospace;" /><span style="font-family: "Courier New",Courier,monospace;"> ENV{ID_AMPLIFIER_PANEL}="1"</span><br style="font-family: "Courier New", Courier, monospace;" /><span style="font-family: "Courier New",Courier,monospace;">ENV{ID_AMPLIFIER_PANEL}=="1", TAG+="uaccess"</span></li>
<li>...that's it. You don't need to do any messing about with groups, you might need to reconnect the amplifier.</li>
</ul>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://1.bp.blogspot.com/-oRBnry5dkBI/T3jtmrSS9NI/AAAAAAAAAIk/Rj56Sq1-KD0/s1600/plug-windows-s.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="310" src="http://1.bp.blogspot.com/-oRBnry5dkBI/T3jtmrSS9NI/AAAAAAAAAIk/Rj56Sq1-KD0/s320/plug-windows-s.jpg" width="320" /></a></div>
<div style="text-align: justify;">
The Plug software isn't as nice looking as the Fuse software, but it does the same job. The only differences are that you can't adjust the USB gain (expect this soon, in the meantime see above for how to do this on the amplifier) and that you must click 'Set' to send any changes to the amp. What's going on is maybe more obvious through the Fuse software:</div>
<ul>
<li>You choose an amp model and edit the normal settings</li>
<li>You can have one of each of four effect types (modulation, stompbox, delay and reverb) and put them in any order. Each effect can be before or after the amplifier model.</li>
</ul>
<div style="text-align: justify;">
When you start Plug, provided the amplifier is connected, it will open and load the settings from the amp. You can tweak these, send them back to the amp, save them to a file or to one of the presets on the amp and you can also load presets from the amp.</div>
<div style="text-align: justify;">
One Fedora tip: some windows wont have a 'close' button, you can right click the title bar and click close. Look out for Plug to be included in Fedora soon.</div>
<br />
<h3>
Windows is easier, right?</h3>
<div style="text-align: justify;">
There's always the suspicion that, when someone is giving you instructions on how to do things in Linux that supposedly work in Windows, they're wasting their time and are some kind of masochist, Linux zealot or anti-Windows anarchist. I like to think I'm none of those. So, here's a quick summary of what I had to do to get all the above working in Windows:</div>
<h4 style="text-align: justify;">
Direct recording</h4>
<div style="text-align: justify;">
Install the Fender ASIO driver and Ableton light (Ableton is a very nice real-time sequencer which you get free with the Mustang). Spend two days reinstalling drivers and trying different soundcards and settings to be able to record without a horrible screeching noise. Finally try plugging into a USB hub. It now works. Why? Who knows?</div>
<h4 style="text-align: justify;">
FUSE</h4>
<div style="text-align: justify;">
Try to run the FUSE and Silverlight installer. Discover your .Net installation is broken. Try uninstalling .Net completely, reinstall. Try again. Find .Net remover from Microsoft support, try this. Eventually discover a reference to a subdirectory in your Windows install that has to be removed to allow class files to be rebuilt.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
I really like both Ableton and FUSE, but that was a painful experience. I hope most people aren't so unlucky with their set-ups.<br />
<br />
<div style="text-align: left;">
<span style="font-size: x-small;">Thanks to Piorekf for creating the Plug software and corrections to this article, Kay Sievers for help with udev rules and many ALSA programmers who make sure that USB sound devices Just Work.</span></div>
</div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-87488479285074488342012-02-19T00:23:00.001+00:002022-03-22T16:08:08.550+00:00Drying out - repairing a pocket pod<div style="text-align: justify;">
Over Christmas my Pocket Pod died. I'd been visiting my parents and noticed this when packing up to leave. Some of my things, including pod were sitting in a mysterious liquid and I wasn't very surprised to see that when I plugged it in it didn't turn on.</div>
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<a href="http://4.bp.blogspot.com/-PQvfpZH8ZZI/T0ArKrcDbUI/AAAAAAAAAF8/fVFbR6KILsU/s1600/DSCN6726_sc-damage-ext.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="320" src="http://4.bp.blogspot.com/-PQvfpZH8ZZI/T0ArKrcDbUI/AAAAAAAAAF8/fVFbR6KILsU/s320/DSCN6726_sc-damage-ext.JPG" width="258" /></a><br />
My first thought was that this slightly brown stuff had come from the pod and that the batteries had leaked. However, opening it up the batteries were fine and there was only the tiniest trace of dry brown powder next to the battery compartment. I was briefly hopeful it was okay, but of course it didn't turn on. This was the start of January and I packed it up planning do something about it later. Over a month passes.</div>
<div style="text-align: justify;">
I briefly wondered whether a capacitor inside had burst, but this was irrelevant as Line6's warranty for the pod lasts an astonishing 90 days. In any case Line6 service centre never replied to an email asking whether they could accept these for repair (to be fair to them, this isn't like asking if they can repair a valve amp head, but reply to your customers' emails guys). There was only one option left.</div>
<div style="text-align: justify;">
<b><span face="Arial,Helvetica,sans-serif" style="font-size: large;"> </span></b></div>
<div style="text-align: justify;">
<b><span face="Arial,Helvetica,sans-serif" style="font-size: large;"><br />
</span></b></div>
<div style="text-align: justify;">
<b><span face="Arial,Helvetica,sans-serif" style="font-size: large;">Cracking the pod</span></b></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-8NZqeONf0hE/T0ArMbv9lFI/AAAAAAAAAGM/XNL41hdjGhk/s1600/DSCN6729_sc-damage-int.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="http://2.bp.blogspot.com/-8NZqeONf0hE/T0ArMbv9lFI/AAAAAAAAAGM/XNL41hdjGhk/s320/DSCN6729_sc-damage-int.JPG" width="320" /></a></div>
<div style="text-align: justify;">
Opening the Pod up is fairly straightforward; remove the four screws and gently prise apart. All the electronics are mounted in the top half-shell, the only connection to the bottom are the wires to the battery compartment. Or, in my case, one of the wires to the battery compartment. And a whole lot of rust-like hard foam. You can see an extra fragment next to the group of four capacitors: this has broken off from around the screw-post.</div>
<div style="text-align: justify;">
</div>
<div style="text-align: justify;">
</div>
<div style="text-align: justify;">
</div>
<div style="text-align: justify;">
So, what's happened is apparently that a <i>tiny</i> amount of water has gotten in and happened to do so via the terminals in the battery compartment. These have happily electrolysed and as a result one of the battery connections has essentially dissolved. Messy, but potentially no other damage has been done provided the battery connection can be fixed. But first...</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-lMEBxSqPGu8/T0ArLMSHzfI/AAAAAAAAAGE/FitLCVddASI/s1600/DSCN6727_sc-tea.JPG"><img border="0" height="200" src="http://2.bp.blogspot.com/-lMEBxSqPGu8/T0ArLMSHzfI/AAAAAAAAAGE/FitLCVddASI/s200/DSCN6727_sc-tea.JPG" width="150" /> </a></div>
<div class="separator" style="clear: both; text-align: justify;">
It seems likely now that the original liquid was tea. Coincidentally this is also essential fuel for any electronics project. Just try not to drop it on anything else.</div>
<div class="separator" style="clear: both; text-align: justify;">
<b><span style="font-size: large;"><span face="Arial,Helvetica,sans-serif">Cleaning up</span></span></b> </div>
<div class="separator" style="clear: both; text-align: justify;">
<a href="http://4.bp.blogspot.com/-XSEeoVb_oaI/T0ArNT7ndPI/AAAAAAAAAGU/0Es68zP_GH4/s1600/DSCN6730_sc-cleaning.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="240" src="http://4.bp.blogspot.com/-XSEeoVb_oaI/T0ArNT7ndPI/AAAAAAAAAGU/0Es68zP_GH4/s320/DSCN6730_sc-cleaning.JPG" width="320" /></a>A bit of cleaning seems appropriate. Mostly done with a paintbrush and dry, though since this stuff was quite stubborn I did wet the brush to try and clean of the last of it. Isopropyl alcohol is probably better if any is available, but I console myself that everything covered in brown has already been wet and unlikely to get any worse. Made sure it was dry before going any further though.</div>
<div style="clear: both; text-align: justify;">
<span face="Arial,Helvetica,sans-serif"><b><span style="font-size: large;">Putting the Rock back</span></b></span> </div>
<div style="clear: both; text-align: justify;">
So, at this point I have a problem. The terminal that the positive lead should be connected to is gone. Or, more accurately, was transmuted into the brown mess I've just removed. Looking at the above picture you can see the negative (black) wire is soldered to a tab coming out of the back of the battery compartment, the corresponding tab for the red wire is missing.</div>
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<a href="http://2.bp.blogspot.com/-Ni_bZySHi8Q/T0ArORK0CsI/AAAAAAAAAGc/xLB5G4nkWOA/s1600/DSCN6731_sc-lever.JPG" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="286" src="http://2.bp.blogspot.com/-Ni_bZySHi8Q/T0ArORK0CsI/AAAAAAAAAGc/xLB5G4nkWOA/s320/DSCN6731_sc-lever.JPG" width="320" /></a></div>
<br />
A fine Allen key makes a handy lever for removing the remaining part of the battery tab...<br />
<div style="clear: both; text-align: justify;">
<a href="http://1.bp.blogspot.com/-EB8WSlN18b8/T0ArPO3Q9KI/AAAAAAAAAGk/MlvHDJ3O41c/s1600/DSCN6734_sc-terminal-gap.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="320" src="http://1.bp.blogspot.com/-EB8WSlN18b8/T0ArPO3Q9KI/AAAAAAAAAGk/MlvHDJ3O41c/s320/DSCN6734_sc-terminal-gap.JPG" width="242" /></a>...and reveals a very fine hole through which it plugs.</div>
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<div style="text-align: justify;">
My plan A was to put a wire through and re-solder at both ends. This isn't going to work. The ideal repair would be to have another of these battery tabs to hand, but of course I don't. I have a brief play with tinning some multi-core wire flat to pass through, but soldering it on the other end is tricky. However I do have a few of these:</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://3.bp.blogspot.com/-eVTwftPbuD8/T0ArP8jpMiI/AAAAAAAAAGs/u2PKor7YgD8/s1600/DSCN6739_sc-crimp-spade.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="216" src="http://3.bp.blogspot.com/-eVTwftPbuD8/T0ArP8jpMiI/AAAAAAAAAGs/u2PKor7YgD8/s320/DSCN6739_sc-crimp-spade.JPG" width="320" /></a></div>
<br />
<div style="text-align: justify;">
If life was easy then this spade crimp would fit through that hole and there would be room on the other side to crimp it on the red wire. Of course neither is true. The spade is both too thick and too wide and the crimp section much too long. Fortunately:</div>
<ol>
<li>I have some pretty heavy cutting pliers.</li>
<li>If you look closely there is a line down the middle of the spade indicating it has been folded to get that thickness.</li>
</ol>
<br />
<div class="separator" style="clear: both; text-align: justify;">
<a href="http://1.bp.blogspot.com/-I9eGcM8W7VA/T0ArQ3GrTvI/AAAAAAAAAG0/EUKqlkhfxjU/s1600/DSCN6740_sc-cut1.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="218" src="http://1.bp.blogspot.com/-I9eGcM8W7VA/T0ArQ3GrTvI/AAAAAAAAAG0/EUKqlkhfxjU/s320/DSCN6740_sc-cut1.JPG" width="320" /></a></div>
<a href="http://3.bp.blogspot.com/-nbK8tgx2d9s/T0ArRpVBMnI/AAAAAAAAAG8/zdFZqQ8UOuE/s1600/DSCN6741_sc-cut2.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="185" src="http://3.bp.blogspot.com/-nbK8tgx2d9s/T0ArRpVBMnI/AAAAAAAAAG8/zdFZqQ8UOuE/s320/DSCN6741_sc-cut2.JPG" width="320" /></a><br />
<a href="http://3.bp.blogspot.com/-ZwGsIIAdREY/T0ArSa9H64I/AAAAAAAAAHA/YhKLYt8LRsI/s1600/DSCN6742_sc-cut3.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="192" src="http://3.bp.blogspot.com/-ZwGsIIAdREY/T0ArSa9H64I/AAAAAAAAAHA/YhKLYt8LRsI/s320/DSCN6742_sc-cut3.JPG" width="320" /></a><br />
<br />
<div class="separator" style="clear: both; text-align: justify;">
And with one more trim to straighten it out we have something that will fit. At this stage all that's left is to solder it onto the battery wire and put the battery terminal back over it (both to press it into place and because the stud is needed to make contact with the batteries, bending the improvised tab in place would be more tricky).</div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://4.bp.blogspot.com/-oRy_1hIh-z0/T0ArS21JGuI/AAAAAAAAAHI/M1YBzYE5t3s/s1600/DSCN6743_s-resoldering.JPG" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="http://4.bp.blogspot.com/-oRy_1hIh-z0/T0ArS21JGuI/AAAAAAAAAHI/M1YBzYE5t3s/s320/DSCN6743_s-resoldering.JPG" width="320" /></a></div>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-ISghj5eC_P0/T0ArTkp5E0I/AAAAAAAAAHQ/jtkwfUgGmqY/s1600/DSCN6744_s-new-terminal.JPG" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="240" src="http://1.bp.blogspot.com/-ISghj5eC_P0/T0ArTkp5E0I/AAAAAAAAAHQ/jtkwfUgGmqY/s320/DSCN6744_s-new-terminal.JPG" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Before putting the terminal back on</td></tr>
</tbody></table>
<div style="text-align: justify;">
The last bit of the old tab had to be removed when putting the new one on.</div>
<div class="separator" style="clear: both; text-align: justify;">
With everything in place, I plug it back in and hope...</div>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://2.bp.blogspot.com/-wadMtZ9JPsI/T0ArUsrCQfI/AAAAAAAAAHY/Zcsk2Gcwu9s/s1600/DSCN6745_s-working.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="http://2.bp.blogspot.com/-wadMtZ9JPsI/T0ArUsrCQfI/AAAAAAAAAHY/Zcsk2Gcwu9s/s320/DSCN6745_s-working.JPG" width="320" /></a></div>
<div class="separator" style="clear: both; text-align: justify;">
So, that's one less distraction from actually playing more guitar.</div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com3tag:blogger.com,1999:blog-3637061929524336435.post-85006929922901911792012-01-23T21:32:00.001+00:002022-03-22T16:08:13.353+00:00Versatile Blogger Award (part 1)<div style="text-align: justify;">Nuno is another regular at the <a href="http://www.guitarnoise.com/" target="_blank">Guitarnoise</a> <a href="http://www.guitarnoise.com/forums/" target="_blank">forums</a>, and writes (or more accurately draws) the <a href="http://vinyleraser.wordpress.com/" target="_blank">Vinyl Eraser</a> blog. He's also possibly the only person who actually reads this blog (Hi! Well, that's not strictly true.) and passed along the <a href="http://versatilebloggeraward.wordpress.com/about/" target="_blank">Versatile Blogger Award</a> to me (thankyou). This gives me a slight dilemma, first I usually avoid chain memes, but this is quite a nice idea which I'd be happy to pass on, except that second I don't really read any blogs regularly, certainly not enough to recommend 15 to anyone. So The Plan is to hold this in reserve until some point in the future. In the meantime, look forward to my attempt to repair a water damaged Pocket Pod...</div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0tag:blogger.com,1999:blog-3637061929524336435.post-80787922431814494782012-01-15T00:52:00.001+00:002022-03-22T16:08:30.684+00:00Ear training, phrase training in Fedora<div style="text-align: justify;">
One of many gaps in my early musical education was good ear training, something I'm now working on fixing. Real tone-deafness is rare, so unless you've actually been tested for it the odds are that if you can't pick out a major from a minor seventh it's because you haven't had enough practice doing it. Fortunately there are now lots of resources you can use to get that practice, so here's a quick round-up of things you can do in Fedora, with a little foray into looping for phrase training.</div>
<a name='more'></a><br />
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
First is online ear training, <a href="http://www.musictheory.net/exercises" target="_blank">Musictheory.net exercises</a> is a good resource which will require Flash support. They have a large selection of customisable exercises (notice a pop-up keyboard at the top right if you need it) and also theory lessons. The format for exercises is that the interval (or chord or note) plays and you then click the correct response, you can replay the example if you're not sure. Lots of resources, though I'm not too keen on the synthesiser sound it uses for the exercises.</div>
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<br /></div>
<div style="text-align: justify;">
But you don't need to be online to use random interval training: <a href="http://www.solfege.org/" target="_blank">GNU Solfege</a> is available in Fedora via the add/remove software tool (or yum if you prefer). GNU Solfege provides a number of configuration options, you can change the instrument it's using and from the front page you pick a class of exercise (e.g. melodic intervals) and then the subtype (e.g. fourths, fifths and octaves). It's not quite as flexible as the Musictheory.net system as, if the particular selection you want isn't there (e.g. all intervals less than an octave), then you'll need to write it yourself; see the <a href="http://docs.solfege.org/3.21/C/extending-solfege.html" target="_blank">extending solfege</a> section of the manual.</div>
<div style="text-align: justify;">
One interesting thing Solfege does have is the ability to use use a different layout for your answers. If you want, instead of having buttons 'major third', 'major fifth' and so on, it can show you a picture of an instrument (including guitar fretboard and piano keyboard) which you click in the correct place to answer.</div>
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<br /></div>
<div style="text-align: justify;">
At the moment I'm not using either of these. I'm listening to <a href="http://www.monkeylord.co.uk/" target="_blank">Rob Chapman</a>'s 'Train Your Ears' CD (downloaded from the Amazon store actually, unlike iTunes the Amazon music store works with Linux). Most of the CD is made up of listening exercises like those the programs above will play you (I just happen to find it easier to listen to a real instrument and don't like pushing buttons, though it also gives you a few ideas for getting started). But there's a problem: you get about a second between the example and the answer. What if you need longer? What if you want to hear it again? This is where I sneak a bit about looping and phrase training into this post.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
I've found two approaches that will work better than hitting pause in Rhythmbox and trying to get the progress bar back to the right place. As a bonus both will also work for anything else you need to be able to replay short sections of and start-stop, such as language tapes.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
<a href="http://audacity.sourceforge.net/" target="_blank"><b>Audacity</b> </a></div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: 0px; margin-right: 0px; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-8NO4wuZ9CaM/TxIXP4OPslI/AAAAAAAAAFs/86W5cUblk6A/s1600/audacity+example.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="215" src="http://1.bp.blogspot.com/-8NO4wuZ9CaM/TxIXP4OPslI/AAAAAAAAAFs/86W5cUblk6A/s320/audacity+example.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Audacity will let you see the different sections.</td></tr>
</tbody></table>
<div style="text-align: justify;">
Arguably <a href="http://audacity.sourceforge.net/" target="_blank">Audacity</a> is the most flexible of the two options. You can install it from the Fedora software manager, but if you want to use MP3 files then you'll need to enable <a href="http://rpmfusion.org/" target="_blank">RPMFusion</a> and install the Audacity-freeworld package instead. As you can see in the screenshot (in which I've zoomed in on the track a little) you can see the loud and quiet sections, which lets you easily select the region you want. You can then play a loop over your selection by pressing <b>shift-space</b> and <b>space</b> to stop. Pressing space will play through your selection just once. To play on you'll next to either extend the selection (drag its right side further along) or drop it or create a new selection. In this case maybe drag it to the short burst (the answer) before the next example. Then select the next example, shift-space and it will play over it again.</div>
<div style="text-align: justify;">
For this purpose Audacity's waveform display also makes it easy to select an example at random. You can use the same thing if you want to listen to language examples or a particular piece of music you're trying to learn.</div>
<div style="text-align: justify;">
Audacity also has a good trick if you want to use it for music, if you open the Effect menu you can select "Change Tempo", this will let you slow a section (or the whole file) down without changing pitch. The results don't sound fantastic (it seems to do very short section looping), but it can be a useful tool.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
<a href="http://www.videolan.org/vlc/" target="_blank"><b>VLC</b></a></div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: 0px; margin-right: 0px; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-JzQI9f1Hx-Q/TxIXQk87vAI/AAAAAAAAAFw/N_rY3r9ZAPo/s1600/vlc-example.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="272" src="http://2.bp.blogspot.com/-JzQI9f1Hx-Q/TxIXQk87vAI/AAAAAAAAAFw/N_rY3r9ZAPo/s320/vlc-example.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">VLC's A-B loop button</td></tr>
</tbody></table>
<div style="text-align: justify;">
To install <a href="http://www.videolan.org/vlc/" target="_blank">VLC</a> you'll need to enable <a href="http://rpmfusion.org/" target="_blank">RPMFusion</a>. While VLC is missing some of the advantages of Audacity (seeing where each example is and fine control of the start and stop locations), there's less fiddling with selections involved. Just start playing, <b>click the A-B loop button</b> to mark the loop start, click A-B loop again to mark the loop end and the playback will loop over this section until you click A-B loop a third time which breaks the loop and carries on playing. Two things to note: the loop button is grey when not being used and you can pause while in a loop (if you need to stop and do something else without looped playback driving you insane).</div>
<div style="text-align: justify;">
Again this works for anything else you need to loop, VLCVLC also supports playlists, unlike Audacity.</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
That's it, obviously there are other (and more sophisticated) options which you may need to investigate if you want to do things like multi-tracking, but the above are useful if you need something quick. I'm off to work on my perfect fourths.</div>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com1tag:blogger.com,1999:blog-3637061929524336435.post-51032781312284298522011-12-12T01:51:00.002+00:002022-03-22T16:08:42.286+00:00Re-amping with Guitarix and ArdourI've been playing about with <a href="http://guitarix.sourceforge.net/" target="_blank">Guitarix</a> and <a href="http://rakarrack.sourceforge.net/" target="_blank">Rakarrack</a> recently. Both are software effects boxes that can be used to model different amps, cabinets and effects chains. But sometimes you just want to play guitar and worry about fiddling with knobs later, or maybe you've put in a great recording, but wish you hadn't put that echo on. This is where re-amping comes in.<br />
<a name='more'></a>Re-amping amounts to recording the clean guitar sound so you can pass it through the modelling again. For this you will need to be able to record multiple tracks, and make connections between your soundcard, effects software and some kind of recording software; fortunately Jack makes this quite easy.<br />
<br />
<b style="font-family: "Helvetica Neue", Arial, Helvetica, sans-serif;"><span style="font-size: large;">Installing</span></b><br />
You will need to install (in Fedora 16 these are all available from Add/Remove software):<br />
<ul>
<li><a href="http://qjackctl.sourceforge.net/" target="_blank">QJackCTL</a> (Jack controller and audio patch editor)</li>
<li><a href="http://ardour.org/" target="_blank">Ardour</a> (Digitial audio workstation)</li>
<li><a href="http://guitarix.sourceforge.net/" target="_blank">Guitarix</a> (Amplifier and effects package)</li>
<li>pulseaudio-module-jack (Jack support for the PulseAudio sound server)</li>
</ul>
<div style="font-family: inherit;">
First set up Jack: start QJackCTL, open the setup menu go to options and add 'pulseaudio -k' to the commands to execute on startup (use a semicolon ';' to separate it from any other commands that are there). You should now be able to start Jack with the 'Start' button. It will cause pulseaudio to restart and connect it up through Jack, so your normal sound wont be affected, but you can now connect everything up through Jack.</div>
<div style="font-family: inherit;">
<br /></div>
<span face=""Helvetica Neue",Arial,Helvetica,sans-serif" style="font-size: large;"><b>Setup and record</b></span><br />
What we want to do is record the clean guitar signal (so we can re-process it later) and, as a bonus, the effected signal, which we'll also play back so you can get a feel for what you're playing.<br />
Start by setting up your input (amp or effects box which is feeding into the sound card or USB) to get a clean signal with lots of headroom<br />
<ul>
<li>Start Ardour</li>
</ul>
We're going to create two recording tracks, one for the dry/clean signal and one for the effected signal. When you first start Ardour you'll need to give it a project name, say okay to keep all the other default settings for now.<br />
Ardour will start with a master track shown, right click in the grey area beneath it and use the 'Add track/bus' box that pops up to add one mono track in normal mode. Click on the track's name box and change it to 'Dry'. Do this a second time and this time create a stereo track called 'Wet'.<br />
<ul>
<li>Start Guitarix</li>
</ul>
We aren't going to do anything with it just yet, if you want to learn how to get the sounds you want out of guitarix see their <a href="http://guitarix.sourceforge.net/" target="_blank">website</a> or the <a href="http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=Main_Page%20" target="_blank">Guitarix wiki</a>, "<a href="http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=How_to_get_a_tone_that_rocks" target="_blank">How to get a tone that rocks</a>" is a good place to start.<br />
<ul>
<li>Start QJackCTL (if you haven't already)</li>
</ul>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://2.bp.blogspot.com/-B6TSUFjjops/TuVT6z7afGI/AAAAAAAAAFc/gz3uRARdnxY/s1600/overview-small.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="261" src="http://2.bp.blogspot.com/-B6TSUFjjops/TuVT6z7afGI/AAAAAAAAAFc/gz3uRARdnxY/s320/overview-small.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Overview of the tools</td></tr>
</tbody></table>
We're going to create a patch (two patches eventually) to connect everything up the way we want, this isn't complex, but it is tedious, so we're going to save them so we can recall it later.<br />
<br />
<b><span face=""Helvetica Neue",Arial,Helvetica,sans-serif"><span style="font-size: large;">Recording patch</span></span></b><br />
In QJackCTL click on the connect button. This will bring up the current connections. It's likely things have automatically joined themselves up, so use the 'disconnect all' button to start from a blank slate. You might want to drag the 'pulseaudio out' onto the 'system in' socket so normal applications can still play sound.<br />
Open the Patchbay with the Patchbay button. Unlike the 'connect' window, which updates connections in realtime, the patchbay doesn't take effect until you activate a patch. Set up your recording patch like this:<br />
<ol>
<li><b>Click the 'Add' button beside Output Sockets/Plugs.</b> Give the first plug the name 'system', choose the 'system' client, 'capture_1' plug and click okay. (We only want to capture mono signal for the input).</li>
<li>Repeat this for the gx_head_amp client 'out_0' plug (call this one 'amp').</li>
<li>Add a third socket for the gx_head_fx client, call this one 'fx'. This time you want to add both 'out_0' and 'out_1' plugs.</li>
<li><b>Now switch to the add button beside 'Input Sockets/Plugs'</b> add the following:</li>
<li>Client 'system' plugs 'playback_1' and 'playback_2' as 'system'.</li>
<li>Client gx_head_amp, plug 'in_0' as 'amp'.</li>
<li>Client gx_head_fx, plug 'in_0' as 'fx'.</li>
<li>Client ardour, plug 'Dry/in 1' as ardour-dry.</li>
<li>Client ardour, plug 'Wet/in 1' and 'Wet/in 2' as ardour-wet, note the 'wet' socket is going to be stereo and the 'dry' one mono.</li>
<li><b>Join the sockets/plugs up</b>, you can do this by dragging the plug names from output sockets/plugs to their targets in input sockets/plugs:</li>
<li>System (capture) goes to amp (in)</li>
<li>System (capture) to ardour-dry (in) </li>
<li>Amp (out) goes to fx (in)</li>
<li>Fx (out) goes to system (playback)</li>
<li>Fx (out) goes to ardour-wet (in)</li>
<li><b>Save</b> click save and give this patch a name like patch-guitarixrecord, because we don't want to do all that twice.</li>
<li><b>Activate</b> click 'Activate' and the patch will go live.</li>
</ol>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-dwxHFoM7Lf4/TuVT7YEWLII/AAAAAAAAAFg/nOj_H5TwDi8/s1600/patchbay.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="217" src="http://3.bp.blogspot.com/-dwxHFoM7Lf4/TuVT7YEWLII/AAAAAAAAAFg/nOj_H5TwDi8/s320/patchbay.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Completed patchbay</td></tr>
</tbody></table>
<div style="font-family: inherit;">
Now that's done you don't have to go through it again. As long as you use the 'Dry' and 'Wet' names in ardour this patch can just be loaded up next time.</div>
<div style="font-family: inherit;">
At this point if your amp and guitar are plugged in and connected to the computer you should be able to play and hear it through guitarix. If you want to hear the clean sound go to guitarix and press <b>B</b> to bypass the engine (because you don't want to fiddle around with this patch again). Press <b>B</b> again to turn bypass off.</div>
<br />
<div style="font-family: "Helvetica Neue", Arial, Helvetica, sans-serif;">
<b><span style="font-size: large;">Recording</span></b></div>
Now you're ready to record in Ardour.<br />
<ol>
<li>Click the recording icon (red circle) next to the 'Wet' and the 'Dry' track titles to enable recording for both tracks.</li>
<li>Click the record button next to the play controls at the top to get ready to record.</li>
<li>Hit the play button to actually start recording.</li>
<li>Play your guitar (I can't help with this bit as will be apparent later) you should see the ardour level meters responding.</li>
<li>Hit the stop button when you're done.</li>
</ol>
<br />
<b><span style="font-size: large;"><span face=""Helvetica Neue",Arial,Helvetica,sans-serif">Play back</span></span></b><br />
This is where the fun begins. Start by unchecking the record box for your dry track (it's perfect, right?). You can listen to the dry or wet tracks, to connect them up you could use the QJackCTL connect dialogue, but it's easier to use the Ardour mixer (Window menu, 'show mixer'). This will show the wet and dry tracks as vertical panels, at the very bottom of both there is a 'comments' button, and above it there is a button which probably shows '-' or '1/2'. Click on the one you want to listen to and select 'out 1+2'. Use the play controls in Ardour to listen to it, when you want to stop listening click on that button and and select 'disconnect'.<br />
<br />
<div style="font-family: "Helvetica Neue", Arial, Helvetica, sans-serif;">
<span style="font-size: large;"><b>Re-amping</b></span></div>
Finally, you've decided your playing is great, but adding a maxed out phaser wasn't such a great idea, or maybe you forgot to turn off bypass in guitarix. What do you do?<br />
<ol>
<li><b>Tear down all the connections</b> (you've saved the patch bay, right?). Deactivate the patch in the patchbay by clicking on the 'activate' button so it's not depressed anymore, then open 'connect' in QJackCTL and click on 'disconnect all'.</li>
<li><b>Make sure recording is disabled on the dry track in Ardour</b>. Also the original wet track, you might have second thoughts after all. It might be a good idea to export the dry track, in Ardour you can select the whole dry track then use Session|Export|Export selected regions to audio file.</li>
<li><b>Create a new stereo track</b>. Call it Remix, or Wet2, or even give it a useful name.</li>
<li><b>Join up the amplifier again</b>. Since this is much simpler than before just do it through Connect rather than Patchbay (also, we might change track names):</li>
<li>Drag Ardour dry (out) to gx_head_amp (in)</li>
<li>gx_head_amp (out) to gx_head_fx (in)</li>
<li>gx_head_fx (out) to Ardour Remix (in)</li>
<li>gx_head_fx (out) to system (in) - if you want to hear what's going on.</li>
<li><b>Adjust Guitarix to your new settings.</b> E.g. you think the track might sound better with a British 12ax7 tube amp and AC-30 cabinet model than an American 6v6 through a 4x12. Better put on some reverb too...</li>
<li><b>In Ardour tick the record button for 'Remix'</b>, make sure it's <b>un</b>ticked for Dry and Wet.</li>
<li><b>Press play</b>. You'll see Ardour progress through the track and lay down the new signal. You're done!</li>
</ol>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://1.bp.blogspot.com/-H1j-dKzo39g/TuVT4yhxJLI/AAAAAAAAAFM/qzEAGQM2QDI/s1600/ardour.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="202" src="http://1.bp.blogspot.com/-H1j-dKzo39g/TuVT4yhxJLI/AAAAAAAAAFM/qzEAGQM2QDI/s320/ardour.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Ardour re-recording our track</td></tr>
</tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-v508-bXtOfs/TuVT5veImMI/AAAAAAAAAFQ/Sv-vfg75TOw/s1600/connect-re-amp.png" style="margin-left: auto; margin-right: auto;"><img border="0" height="163" src="http://3.bp.blogspot.com/-v508-bXtOfs/TuVT5veImMI/AAAAAAAAAFQ/Sv-vfg75TOw/s320/connect-re-amp.png" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Connections for re-amping</td></tr>
</tbody></table>
Of course you could leave out recording the 'Remix' track while you play back and tweak the Guitarix settings.<br />
<a href="http://soundcloud.com/imalone/sets/ardour-guitarix-re-amping" target="_blank">Here's an example</a>, first the dry recording then an attempt at two different gain tones.<br />
<br />
<div style="font-family: "Helvetica Neue", Arial, Helvetica, sans-serif;">
<span style="font-size: large;"><span face=""Helvetica Neue",Arial,Helvetica,sans-serif"><b>Useful links:</b></span></span></div>
<a href="http://www.linuxjournal.com/content/introducing-guitarix" target="_blank">Linux Journal</a> on Guitarix - Guitarix has moved on quite a bit in the two years since, but this is a nice overview.<br />
<a href="http://rakarrack.sourceforge.net/" target="_blank">Rakarrack</a> is another Linux effects box and can do exactly the same thing.<br />
<a href="http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=Main_Page" target="_blank">Guitarix wiki</a> for hints on getting your sound, see "<a href="http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=How_to_get_a_tone_that_rocks" target="_blank">How to get a tone that rocks</a>" for a quick intro.<br />
<a href="http://ardour.org/" target="_blank">Ardour</a> because I haven't been using it long and I'm sure there are improvements you could make to this workflow.<canvas height="4126" id="basicGestCanvas" style="height: 4126px; left: 0px; overflow: visible; position: absolute; top: 0px; width: 686px; z-index: 10000;" width="686"></canvas>justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com3tag:blogger.com,1999:blog-3637061929524336435.post-3561282108147712242011-11-28T23:40:00.001+00:002022-03-22T16:08:50.092+00:00Pocket Pod Tux<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://3.bp.blogspot.com/-mdmv0nNh3fI/TtNQDNCdQQI/AAAAAAAAAE0/dqXnymFnAmI/s1600/pockettux.jpg" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="278" src="http://3.bp.blogspot.com/-mdmv0nNh3fI/TtNQDNCdQQI/AAAAAAAAAE0/dqXnymFnAmI/s320/pockettux.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;"><span style="font-size: xx-small;"> Tux created by <a href="http://www.isc.tamu.edu/%7Elewing/linux/" target="_blank">Larry Ewing</a> lewing@isc.tamu.edu</span></td></tr>
</tbody></table>
<div style="text-align: justify;">
One of the cheapest and best known options for guitar multi-effects is the <a href="http://line6.com/pocketpod/" target="_blank">Line 6 pocket pod</a>. It's been around for a while and I'm not going to review it, except to say it produces sounds and like any modeller it gives you the option of trying out different tones. What we're interested in here is that it can be tweaked from your computer via USB.</div>
<a name='more'></a><div style="text-align: justify;">
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There are reasons you might want to do this other than just geekery. One is that the Pod's four dials are all dual function, but can only be in one position at a time. This means if you set the delay level then try to tweak treble the treble is changed to whatever position the dial was at. Even if you don't find that annoying, using a computer lets you see where all the settings are at once, tweak them independently and also change things that you can't change with just the dials. I also find it handier to set the Pod down and adjust things via the computer than pick it up and fiddle with knobs.</div>
<div style="text-align: justify;">
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<div style="text-align: justify;">
How do you do it? Line6 provide their <a href="http://line6.com/software/" target="_blank">Vyzex software</a> for Windows and Mac, but nothing for Linux. However things are actually straightforward, because Vyzex runs happily in <a href="http://www.winehq.org/" target="_blank">Wine</a> and, despite using it for slightly unusual ends, the Pocket Pod talks like a Midi device. So in Fedora 16 what you need to do is this:</div>
<ol style="text-align: justify;">
<li>Install Wine, x86 version (yes, even if you're using 64bit Linux). At the time of writing you need version 1.3.33-1 on Fedora, so install it from the command line like this:<br />
<ul>
<li>su -c 'yum update --enablerepo=updates-testing wine-1.3.33-1.fc16.i686' </li>
</ul>
</li>
<li>Download the Windows version of the <a href="http://line6.com/software/" target="_blank">Vyzex software</a> (you'll need to create a Line6 account)</li>
<li>Extract it and then right click on the .exe in the file manager and open it with Wine</li>
<li>You can now start Vyzex from the Applications - Other menu.</li>
</ol>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
I could stop writing now, but some people object to Wine and having to use Windows apps. Also open source options give you scope to do things the original designers didn't foresee. What are the options?</div>
<div style="text-align: justify;">
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<div style="text-align: justify;">
Since the Pocket Pod speaks Midi, Linux Midi programs can talk to it. However it mainly presents a bank of controls, so the big one, Rosegarden which is aimed at sequencing, doesn't really present a useful interface. Two pieces of software do:</div>
<div style="text-align: justify;">
<br /></div>
<div style="text-align: justify;">
<a href="http://www.jsynthlib.org/" target="_blank">JSynthLib</a> is a synthesiser patch editor which supports the Pod 2.0, basically the original version of the Pocket Pod. You can download it and then start it (with the Pod attached first!) by:</div>
<ul style="text-align: justify;">
<li>java -jar JSynthLib-0.20.0.jar</li>
</ul>
<div style="text-align: justify;">
It's not immediately obvious how to get to the controls:</div>
<ol style="text-align: justify;">
<li><a href="http://4.bp.blogspot.com/-Z-x_Y-jPvEY/TtQYJMwunsI/AAAAAAAAAFA/I7tO7STgJp0/s1600/jsynthliboverview.png" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="231" src="http://4.bp.blogspot.com/-Z-x_Y-jPvEY/TtQYJMwunsI/AAAAAAAAAFA/I7tO7STgJp0/s320/jsynthliboverview.png" width="320" /></a>Go to Window - Preferences, check the Midi tab, that Midi is enabled and POD is selected for input and output.</li>
<li>Start a new library (left hand icon, or Library - New Library)</li>
<li>Select Patch - Get then in the new window 'Get' followed by 'Done'. This is the weakest point, it looks like it should be possible to import all the presets at once like the Vyzex software can, but actually you'll only get one preset at a time. If you're worried about overwriting the presets then select the 'Edit buffer' driver when choosing the patch.</li>
<li> Right click on any patch and click 'Edit', this will bring up all the knobs you can tweak and they'll update the Pod in realtime.</li>
</ol>
<div class="separator" style="clear: both; text-align: center;">
<a href="http://4.bp.blogspot.com/-HDSaSjhiOIA/TtQYIXJwu1I/AAAAAAAAAE8/OhiEJL_9sH8/s1600/jsynthlibcontrol.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="179" src="http://4.bp.blogspot.com/-HDSaSjhiOIA/TtQYIXJwu1I/AAAAAAAAAE8/OhiEJL_9sH8/s320/jsynthlibcontrol.png" width="320" /></a></div>
<div style="text-align: justify;">
If you're feeling more adventurous you could try <a href="http://sourceforge.net/projects/jpodeffects/" target="_blank">JPod</a> which is written specifically for the Pocket Pod. It's not well maintained and only available as source code. Problems include the widgets being very oversized, but it will read the preset bank. For those determined to give it a go:</div>
<ul>
<li>git clone git://jpodeffects.git.sourceforge.net/gitroot/jpodeffects/jpodeffects jpodeffects</li>
<li>ant jar</li>
<li>java -jar bin/JPod.jar</li>
</ul>
I'm sure someone with some Java Swing experience could easily improve on it a bit.justianianhttp://www.blogger.com/profile/02876077055591144551noreply@blogger.com0