Available as an assembled Module and as a DIY project.
This Module is currently available.
GGS 3320 VCF / Voltage Controlled Lowpass Filter
Guru Gara Synth / 3320 VCF
This module is a typical voltage controlled low pass filter design based on CEM3320. It can create from low rubbery bass to high resonance screaming synth sounds. It is a simple design with audio I/O, CV in, CV amount, resonance and the cutoff frequency. 3320 design was used in the 80s by many synth brands such as Oberheim, Sequencial One just to name a few. Front panel is also made out of PCB and screen printed by hand.