Casper Electronics

The Benjolin is a relatively simple but wonderfully clever analog, complex sound generator designed by synth pioneer Rob Hordijk.

Here’s what Rob has to say about it on his website.
“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.”

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SOUNDS:

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Here’s all the info that Rob has put online about building your own Benjolin:
*Benjolin forum*
*Instructions*
*Schematic*
*PCB*
*PCB parts layout*
*Parts list*

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Here’s a slightly modified version of the schematic I put together.
New Schematic
The original version (linked above) 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 around this awesome circuit. I’ve listed a few modifications and additions worth checking out if you are considering building your own.
The mods can be found here.