Ian Fritz designed an awesome hyperchaos circuit and gave me the go ahead to let it loose on Eurorack.
You can read the discussion on this design on the muffwiggler thread
This is Ian's introduction in his article on the circuit: The Hypster is an electronic fourth-order hyperchaos generator for use in modular electronic music systems.
Hyperchaos is chaos on steroids, with the mathematical divergences being generated in more that the usual single dimension. The module is a unique, original design featuring voltage control of the main system parameters.
In synthesizer applications this module can produce signal waveforms varying from simply periodic to complicated multiperiodic to extremely dense and complex, both in the low frequency control range as well as up into audio frequencies. With an eight-signal output it can simultaneously control a large number of synthesizer parameters or generate multiple audio waveforms for individual processing.
The circuit is built around four voltage-controlled integrators connected in a ring, similar to the configuration of an oscillating ladder filter. But that is where the similarity ends. Each integrator includes damping, making the system more like the 6/8 phase oscillator described on my website. Most importantly, special circuit elements between the four integrators provide the nonlinearities required to produce chaotic oscillations. The gain and resonance of one of the stages may be varied. Varying these parameters produces a wide range of periodic and chaotic signals. These
parameters, along with the overall oscillation rate are under voltage control.
It is very wide ranging, from approx 3kHz down to 5 minute orbits, capable of a huge variety of patterns and is particularly partial to being controlled by various CV signals.
PCB set = USD26
White Panel = USD24
Black Panel = USD25
'B' stock black panel = USD20 (these have some very minor defect; scratch or dust under soldermask)
assembled = USD250