Chaos 01 is a minimal chaotic drone built entirely from elementary VCV stock modules. By Brian Greenforest. Free and open under the MIT license.

The deterministic chaos core is eight CV Mix modules and two VCA modules: ten modules in 30 HP. The complete playable sound patch has 15 stock modules and 27 cables. No dedicated chaos module or script is required.

The target equations are:

dx/dt = y
dy/dt = -x – y*z
dz/dt = y*y – 1

Mixers add voltages, linear VCAs form the products, and three unity-feedback paths accumulate state. This is a sampled implementation of the Nosé–Hoover / Sprott A system. Noise is used only in the sound path; it does not drive the mathematical core.

GETTING STARTED

Open the supplied .vcv file in VCV Rack 2. Set the engine sample rate to 48 kHz, then select your own audio driver and output device in Audio-2. The saved device is MacBook Pro Speakers. Start at a low listening level and let the patch evolve.

The patch starts near (0, 0.1, 0). Reopen the supplied file to restart it. Do not initialize the modules: that resets the calibrated gains.

Reading from the left edge, x is the output of module 4, y of module 3, and z of module 7. These three state outputs are useful modulation sources for your own patches. Here they control VCF cutoff, resonance and drive, with filtered red noise and an FM-modulated VCO sine mixed at the output.

LISTEN AND READ

Full article, equations, module map, audio player and license:
https://greenforest.io/chaos-01.html

Two-minute MP3:

Download the 48 kHz / 24-bit WAV: https://greenforest.io/synthesis/chaos-01-120s.wav

The render uses the actual Rack 2.6.6 engine and VCV Free 2.6.4 modules with the saved patch’s signal graph and settings. Capture preserves the output’s DC filter; only a constant playback gain and edge fades were added.

The download includes the original .vcv patch, setup instructions and the MIT license. Copyright (c) 2026 Brian Greenforest.