In the past few months we developed a “vdPol oscillator and filter”. This device, named after its founder, is an interesting circuit which consist of multiple integrators (inverting opamp-circuit with an capacitor as feedback component) in a loop with signal multipliers (4-quadrant multiplier = AD633) .
I made multiple versions of the vdPol oscillator that can be used in combination with analogue studio Bea-5 (banana connectors) and the Doepfer set (mini jack connector).
At this point we still think the design of the vdPol can be improved. The tweaking and search of stability versus interesting sounds and behaviour is still in progress. To make the experimenting and tweaking more interesting, I designed a printed circuit board. Now more vdPol oscillators and filters can be connected together in one chain (or feedback-loop), creating very rich audio-patterns.