SSM2044 VCF DIP NOS

SSM2044 VCF DIP NOS

The SSM2044 is a 4-pole lowpass filter chip used in a number of synths including the PPG Wave 2.3, the Korg Monopoly, Polysix, and Trident, Seil Opera6 and others.
 

The datasheet suggests using the two differential inputs (+audio and -audio) as individual oscillator inputs for a two-oscillator synth (or synth voice). It also suggests that these two inputs should be provided with slightly different resistor values (68K Vs 100K) so that the oscillators don’t cancel completely when beating against each other.

* SSM2044 Filter Schematic (above)