Wednesday, 1 July 2015

NLC JerkOff - Chaos Module - Build notes

This is a really cool chaos module & is super easy to build.  It uses chaotic oscillators based around Jerk Equations. It's a excellent source of CVs - for modulating & controlling filters, VCOs, mixing with envelopes, etc etc

Andrew's build notes for the single Jerkoff module are here:
http://www.sdiy.org/pinky/data/single%20JERKOFF.pdf
Build notes for the double JerkOff are here:
http://www.sdiy.org/pinky/data/DOUBLE%20JERKOFF.pdf

WAMOD - More Notes

Much of the original research & design was done by J. Sprott of the University of Michigan.
You can read his paper (in PDF format) here:
http://sprott.physics.wisc.edu/pubs/paper352.pdf

The circuit consists of two feedback loops. The first involving 3 integrators.
The second uses two integrators and a inverter/diode. (Intergrator's are common to analog computers)
I  understand this is described as a chaotic phase-shift oscillator ... consisting of an inverting amplifier (the 741 opamp??) with its output fed back to its input through a phase-shift network consisting of resistors and capacitors.

Here are some pics of the NonLinearCircuit PCB:
The circuit has 3 outputs: X, Y,  Z and 1 input ‘in’. 
Feeding it gates or triggers should get the output signals to sync with other modules.

Headers first:. Resistors & caps next
Andrew has left this module open to lots of experimentation. Above are the marked caps & resistors.

The rest of the component values are very much up to you to pick. I've decided to use 100K B pots.
It's recommended to use resistors with half the value of the pots.... thus 47K ohms are the closest.

These 3 caps are the ones you choose to set the base frequency. I've picked 1uF.
 The rest of the caps are for decoupling. There are 4 of these. ....any value between 10nf & 100nf is fine. I've used 47nF.

The pots are all 100k Linear.

Time to install the LEDs.
I've placed these on the front panel. These LEDs are the superbright variety though I'm not sure of their exact forward voltage or current so I'm experimenting a bit ....using a 10k resistor for now.
(The LED resistor is marked as RL on the PCB) 

Testing the initial build.

LEDs seem to be working.... haven't burnt out yet. :-)
Decided to leave the LEDs where they are for now. Should have cut the legs longer.




     Useful Links
1. Chaos Theory & Jerk Circuits
2. Mongol/Jerkoff - Youtube Video
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Click here to return to the NLC Build Index:
http://djjondent.blogspot.com.au/2015/03/non-linear-circuits-ncl-index.html

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