via this auction
SN 2331
"The CS-30 is a large, knob infested, analog synthesizer with masses of features. It is a monophonic synth with two oscillators with separate outputs, two multimode resonant filters, two VCA amplifiers and three envelopes. It also features a ring modulator, external audio triggering and an excellent 8-step sequencer.
Great sounding with a vast range of possibilities for sound shaping and modulation based experimentation. It can be punchy and fast, richly textured or funky as hell. The closest you get to a semi-modular without patch cords. This machine is a sound designers dream."
