TEMPORARILY DISCONTINUED
The Grackler Core is a circuit with four unusual VCOs cross modulating one another in a ring specifically designed to create a sort of polyphonic entropic voltage source. The VCOs go from so high that they are well above human hearing to so low that below a certain threshold they freeze and store an unpredictable LOW or HIGH state until they receive enough juice to kick them back into seesaw action. Each VCO has three distinct ranges selectable via toggle switches.
The VC Band Pass Filters are OTA-based state-variable filters with very interesting and adjustable overload characteristics. You can process signals from the Grackler Core or external signals through the filters via the green banana jacks. I would recommend first trying the XOR outputs. With frequencies low and input levels set low, Serge-esque filter pings are produced. Overloading the input stages, plugging in audio rate FM signals and cranking the resonance (or any combination of these) produces chaotic behavior and unpredictable timbres.
The 12 outputs available from the Grackler Core include sawtooth waves, rectangle waves, XOR compared squares, and stepped waveforms derived from two differently weighted sums of the four VCOs. These outputs can also be stacked via banana cables to create even more complicated waveforms. When used in the high frequency ranges, the Grackler Core also works as a flexible voltage controlled noise source. Lastly, the complexity of the Grackler Core can be further enhanced by plugging in an external signal in place of the internal reference voltage assigned to the MACRO knob. Even simple CV sources like LFOs, gates and step sequencers can dramatically ramp up the insanity.