“The Yamaha CS30 is an analogue keyboard synthesiser that was released in 1977. It is large and knob infested, with extensive analogue control and shaping. It has two oscillators with separate outputs, two voltage controlled resonant filters, two voltage controlled amplifiers and three envelopes. It also features a ring modulator, external audio triggering and a simple but useful eight step sequencer for use as a sketch pad, pattern or arpeggio effect. It does not have any on board effects, memory nor MIDI. Although it is just a monophonic synthesiser with a short forty-four note keyboard it offers a lot of programming flexibility.
Please note it has been kept in storage and has not been used for quite some time. Therefore it is not in good condition and in need of some attention, for example, the sequencer can be temperamental. It would suit an enthusiast who knows a bit about them, either for refurbishment or spare parts. There are no other items supplied, connecting cables, instructions etc. What you see in the photos is what you get.
Please also note this complicated heavyweight beast is not really suitable for a beginner!” lINK