The Pro VCF is a faithful adaptation of a well-known 4-pole synthesizer filter in Eurorack.
The core of this design lies an Alfa AS3320 filter chip based on the original Curtis. Countless synthesizers used the 3320: Sequential Pro One, Prophet 5 rev 3, Drumtraks, Crumar Trilogy, Stratus, Elka Synthex, some Fairlight CMI, Linndrum, Oberheim OB-8, OB-Xa, PPG Wave 2
At full resonance the Pro VCF can self-oscillate.
FEATURES
Two selectable filter slopes: original 24 db/oct, and 12 db/oct.
Two voltage controlled input jacks for frequency CUTOFF w/ signal attenuators.
A voltage controlled input jack for RESONANCE w/ a signal attenuator.
Two signal input jacks w/ individual attenuators. At full clockwise, these inputs can overdrive the filter from most eurorack oscillators and audio sources.
More details at Modular Grid
