Wednesday, 9 March 2016

Squid Axon

Just the module everybody has been waiting for! A squid brain cell simulator!

The Squid Axon is a circuit based on the Hodgkin-Huxley equation describing the chaotic behaviour observed in giant squid axons. The inspiration for the module came from a 2003 paper by T. Matsuzaki & M. Nakagawa, titled 'A Bipolar Logistic Chaos Neuron and Its Hardware Implementation'.

Basically it is a four stage analog shift register with two feedback paths, one nonlinear and one linear (I do try to walk the line). If you turn the feedback paths down to zero, you get a regular ASR. Turn up the feedback to get more complex and staggered patterns from the 4 CV outputs. It will happily run at audio rates as well.

These two pictures show the 4 outputs as a tri-wave is sampled and shifted thru:


  1. Best idea ever to bring this idea to euro

  2. Hi Andrew! Any chance we'll see some sort of Squid Axon Deluxe in the future? I would love to have VCAs in the path of the linear and nonlinear feedback so they could be voltage controlled!

    1. Bridge the pots with vactrols and drill holes for jacks. Not the cleanest solution, but effective!