Description: Ian Fritz’s circuit produces chaotic oscillations according to a third-order differential, or ‘jerk’, equation. The panel, bracket, and PCB are available from Bridechamber:
In as simple terms as I can describe, there are three outputs, each of which produces sinusoidal waveforms. The outputs have some correlation, especially the frequency. The frequency range is pretty wide. I have used it so far in the LFO range, where it is great for spooky vibrato, and in combination with a comparator produces interesting random gates. I don’t understand just what the MOD CV modulates, but it changes the character of the outputs. In fact, I can’t say I understand this module much at all! But it’s a good source of smoothly varying random voltages.
Here is a detail of the circuit board. The PC board is not high quality, but it’s a simple circuit. It was a bit of a chore to file down the pins on a MOTM power connector to fit the too-small holes in the board. I ran a wire soldered to the ground pins at the power connector out to ground the panel jacks and did not use the tiny ground pad – pin 15. Although you could use a 16-pin header and a connector, it seemed too much trouble, so I just soldered wires into the header pin holes.
Here is another picture of the construction. I used inexpensive Alpha carbon pots, the shafts fitted with #5 O-rings from Lowes plumbing department to seat them into the 3/8-inch panel holes. After finding that the Rate pot has a large range and is very sensitive, I am considering replacing it with a 10-turn pot. The Bridechamber 3-jack bracket works, but despite having a lot of holes to match various PC boards, none matched the Jerkster and I had to drill my own. I cut off the unused portion of the very long bracket.