KAOS

Next module: A Kosmo conversion — a konversion — of the Nonlinear Circuits Sloth Chaos.

This is a chaotic CV generator. It outputs a CV that varies smoothly and not very rapidly, but doesn’t follow a regular pattern. It usually sort of kind of approximately repeats itself every 15 seconds, but not exactly, and not always — sometimes it switches into a different mode of behavior. You can see a demo (not mine) here:

15 seconds for the not-so-slothful “fast” version, anyway. You can use different component values to make three other versions, with the slowest cycling about every one and a half hours. I dunno, when I build a new module and plug it in, I want to know immediately if it works — I don’t want to take several hours to find out!

In fact mine didn’t work when I first tried it, several weeks ago. I put it aside while I focused on other things. Today I got back to looking at it and discovered I’d completely skipped soldering one of the pins on the IC socket. I fixed that and it worked.

I did say “IC socket”, singular. It’s a very simple circuit, one quad op amp chip and some resistors and capacitors, and a bicolor LED that shows the state it’s in. (For the slow version the LED may not change color for a couple of days.) The PCB is correspondingly small, intended for a 4HP Eurorack module.

And indeed I might have done this as Eurorack, considering it has only one knob and two jacks so doesn’t really need Kosmo’s larger scale, except the Eurorack panel costs $20 and I didn’t feel like spending that. And, okay, I do have a couple 4HP blanks around here, but I decided as long as I was repaneling it I might as well go Kosmo. I built the board standard except I replaced the board mount jacks with wires connecting to the big jacks. That deprived the board of part of its mounting arrangement, but the board mount pot holds it in place well enough and a piece of foam wedged under the bottom end stabilizes it for plugging in power.

For the front of the panel I used my currently preferred method of printing graphics on paper, gluing it to the panel, and covering it with self adhesive clear plastic.

It’s a fun module. I’ve been trying out running it through the quantizer. That’s good when the CV is positive. Unfortunately the quantizer rejects negative CVs, just outputing zero volts, which is kind of the opposite of chaos. It’s a significant drawback to that design. Someday maybe I’ll come up with a version of dac/ino that will handle bipolar input. A lot sooner, I think I’ll build something that’ll do conversion between ±5V and 0–5V. Anyway, chaos is upon us and that’s good.

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