The Benjolin is a relatively simple but wonderfully clever analog, complex sound generator designed by synth pioneer Rob Hordijk.
<img src="http://web.me.com/klangbureau/DIY/Benjolin_files/WS-kits-2.jpg" alt=""  width="400" height="300" />
Here's what Rob has to say about the Benjolin on his <a href="http://web.me.com/klangbureau/DIY/Benjolin.html">website</a>.
<em>"The Benjolin is a ‘noise box’ that is ‘bent by design’, meaning that it always has a definite amount of unpredictability while it is still intuitive to play. The Benjolin features two eighteen-octave range voltage controlled oscillators that drive a ‘rungler’ circuit, circuitry that in essence uses a special interference technique feeding back into the oscillators to force them into wild chaotic behaviour.
A special slightly chaotic filter is both excited and modulated by the signals from the rungler circuitry processes, producing sounds between fat drones to grungy noise havoc." </em>
Rob has posted a bunch of Benjolin info <a href="http://electro-music.com/forum/topic-38081.html">HERE</a> including schematics and a thorough description of how it all works.
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SOUNDS:
<embed type="application/x-shockwave-flash" flashvars="audioUrl=http://web.me.com/klangbureau/DIY/Demos_files/BL-2.mp3" src="http://www.google.com/reader/ui/3523697345-audio-player.swf" width="400" height="27" quality="best"></embed>
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Here's all the info that Rob has put online about building your own Benjolin:
*<a href="http://electro-music.com/forum/forum-185.html">Benjolin forum</a>*
*<a href="http://electro-music.com/forum/topic-40834.html">Instructions</a>*
*<a href="http://electro-music.com/forum/phpbb-files/benjolinschematic_164.pdf">Schematic</a>*
*<a href="http://electro-music.com/forum/phpbb-files/benjolinpcbv2_732.pdf">PCB</a>*
*<a href="http://electro-music.com/forum/phpbb-files/benjolinv2layout_494.pdf">PCB parts layout</a>*
*<a href="http://electro-music.com/forum/phpbb-files/benjolinbillofmaterials_168.pdf">Parts list</a>*
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Here's a slightly modified version of Robs schematic. 
<a href="http://casperelectronics.com/images/finishedpieces/benjolin/NewSchematic.jpg">New Schematic</a>
Robs version of the schematic is spread over 4 pages. I've consolidated it to one page and made a few changes to the labeling in order to make it easier for myself to read.
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I've been working with the Benjolin a whole lot over the past year or so. See the links at the top of the page for some of the pieces I've built using the Benjolin. I've listed a few modifications and additions worth checking out if you are considering building your own Benjolin. 
The mods can be found <a href="http://casperelectronics.com/finished-pieces/benjolin/modular-benjolin/">here</a>.