Voice of Saturn VCF

4-pole resonant low-pass filter

the VOS voltage controlled filter is based around a CEM3372 filter IC (4-pole resonant low-pass filter)--the same chips found in the filters of such analog classics as the sequential circuits prophet 600, prophet t8 and oberheim xpander. it features two inputs that are summed and then fed into the low-pass filter. the input and output volumes, cutoff frequency and resonance can all be controlled by VC (voltage control) and knobs.

one very cool feature of the cem series filter chips is that as the resonance is turned up, the volume level does not drop as dramatically (as it does in other analaogs, including the famous moog ladder filter).

http://www.analoguehaven.com/thevoiceofsaturn/voltagecontrolledfilter/manual.pdf