Hjk Chaos Bundle - chaotic generators (update for 0.4.xx in progress!)

this is an experimental (meaning i have to refine it a lot) unit inspired by the tips by Rob Hordijk about chaos generators.
this one is inspired by the phase modulation chaos gen.
sine osc phase modulated by itself thru a s&h , the output also influences the frequency of the clock triggering the s&h.
here the link to Rob Hordijk synthesis workshop:
and here’s the .lua:
HjkchaosPM2.lua (23.7 KB)

here an example of how it sounds. these are two instances hard panned left right (i think it’s more interesting as a modulator tho):


try using it as a chaotic gate generator to trigger samples or adsr’s

1 Like

another one, this time is the simpler one based on a pulse wave oscillator (in this case a clock\hz unit) whose frequency is modulated by its output filtered by a LPF. some of the settings result in a steady sound while when the chaos kicks in the circuit stabilizes itself on a regular pattern. still have to investigate if the circuit is actually a true chaotic generator. feedback very welcome!!!


  • freq: controls the frequency of the pulse oscillator (summed with the output of the LPF section).

  • div: another control for the frequency of the pulse oscillator (being a clock generator in fact). think of it as a coarser control.

  • index: amount of linear frequency modulation (how much the filtered pulse out modulate its own frequency).

  • pw: pulse width of the pulse oscillator.

  • cutoff: frequency of the low pass filter.

  • q: resonance of the low pass filter.

DO NOT TOUCH the OSC and LPF parameters, they are there for routing needs only.
the circuit can go mute. in that case the fastest thing to do is increase Q.

HjkchaosSq1.lua (11.2 KB)


Will check this out for sure - this is exactly what I’m interested in :slight_smile: thanks for sharing

1 Like

Great one, thanks!

1 Like

niiiiiceeee! still in line for a 301 to get shipped out to me, was just wondering about chaos Units. this looks/sounds AWESOME.


1 Like

I will continue to post here the new (read: compatible with 0.4X firmware) chaos units. next in line is the Hjk Phase Chaos (former HjkPM2 unit).
this time it adhere perfectly to the Hordijk paper and behaves pretty well.

Hjk Phase Chaos
This generates chaotic patterns using a self phase modulating sine thru a s&h with a sweepable offset. Use it with slow clocks as pitch source or to modulate any parameter. Clock it with an audio rate oscillator for nasty digital noise chaos.
This custom unit requires firmware 0.4.xx


  • clock: this triggers the s&h. can be driven at audio rate. it reacts to the pulse width of the clock signal
  • seed: this controls an offset (from 0.1 to 1) which ensures the feedback mechanism doesn’t freeze on 0 values, and can be used to slightly modify the chaotic behaviour.

Hjk Phase Chaos.unit (7.8 KB)

edit 1: changed the clock from trigger to gate so it is now sensitive to pulse width of the clock signal


Hjk Phase Chaos is super cool! I’m using it from a global chain to fire resets and punch ins on feedback loopers…Fun! Thanks for making it.

1 Like

I hope you used that money from the muff’s sale to fund your new er301 :slight_smile: I picked up one of your modules, nice to see you over here.

Welcome to the rabbit hole that is the er301 (in a completely great way ofcourse!).


1 Like

You encapsulate the spirit of a right angled philosophy! “Es seguro” and although I don’t understand what you drive at, completely, your excitement inspires me to learn… thankyou

1 Like

Hjk Square Chaos

This unit generates chaotic behaviour by having a pulse oscillator (Accents Aliasing Pulse) modulating its own frequency thru a resonant, sweepable, low pass filter.


  • tune: v/oct input of the pulse oscillator
  • index: how much the output of the lp filtered pulse wave modulates its own frequency
  • cutoff: cutoff frequency of the low pass filter processing the pulse out that then modulates oscillator frequency
  • q: resonance of the low pass filter processing the pulse out that then modulates oscillator frequency
  • pw: pulse width of the pulse oscillator

Hjk Square Chaos.unit (11.2 KB)


here the link to the new one, Hjk Rob Chaos :