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.
Experimenting |
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.
Layout |
Adapted schematcis |
Almost there |
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 |
Victory ! |
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 |
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