|Ready to be mounted in synth|
This module produces two different, very slow, chaotic CV signals. It is my implementation of the Non Linear Circuits Sloth Chaos. I chose the regular version with 1 cycle every 15-20 seconds. Depending on component values, other versions include Apathy (about 1 minute), Super sloth (15-20 minutes) and Stasis (about 1.5 hour !).
I needed to accommodate the values to match what I have on my drawers. I tested on a breadboard to see if little changes on some components values would make a difference. It turned out that yes, it does make a big difference. It looks like there is a pretty good balance between the feedback and the small signal, going to the integrator for the big signal. The torpor potentiometer plays with that balance. But go with 20% more or 20% less resistance on that path and you end up with either two synchronous, though out of phase and saturated signals, or two chaotic but very small signals.
I did not have 91k resistors, 82k + 10k would do the trick. 100k was too high, 82k too low. Same with the 4.7M, replaced with 2x 2.2M.
I also made a small change in the original schematics. I wanted to have the LED be less than a negative/positive indicator and follow the signal a bit more. So I chose the output of the buffer after the small signal output instead of the output of the following opamp.
The main board is really cramped. Those 1uF capacitors were bigger than expected. I really had to be very cautious on some connections. It's a little bit of a mess at times, but I'm quite happy with the result.
|The two boards before assembly|
After some minor corrections to both the layout and the wiring of the boards, I finally got the familiar chaos attractor pattern on the oscilloscope.
Torpor potentiometer does not have a lot of effect. Tough it seems to me that the signals are spending more time around a stable state (i.e well) when the pot is maxed out.
|Marking holes before drilling|
|Bob cutting the hole for the potentiometer|
And now a bit of sound.
We have here two saw waves originally in tune. One of them detuned by Sloth small signal.
The filter cutt-off frequency is modulated by Sloth big signal.
Low Pass output goes to the phaser.
Band Pass output goes to Rings to Rings, modified by Sloth and output from sample & hold.
Rythmic gate from TAL Filter 2 and reverb from Voxengo OldSkollVerb in Reaper.
No VCA was harmed during the making of this piece.
This seems to put a close to the bottom row of the synth suitcase.
|Synth suitcase bottom row|