The instrument
The CS-40M is a duophonic analog synthesizer that was introduced in 1979. It is like a 2-voice version of the CS-20m. It offers 4 VCOs, multi-VCF (LPF/BPF/HPF), VCA with sub-oscillators, VC-LFO with its own envelope, ring modulator, 3 envelopes, monophonic/duophonic mode (2×2 VCOs or 1×4 VCOs), 20 memory locations and a cassette device.
Details
The VCOs have a 6-stage octave selector switch (64′ to 2′). The waveforms are sine, sawtooth and the pulse wave, which can be modulated. Numerous modulation sources can be found in the Function section: The waveforms of the LFO (sine, sawtooth+, sawtooth-, pulse wave, S/H), the separate third envelope (EG+ and EG-) as well as external inputs for VCF and VCA. The VCF filter offers the operating modes LowPass, BandPass and HighPass. The VCA can be used to add two sine waves to the oscillator signal. Various sound effects can be achieved with the ring modulator. The LFO can be adjusted far into the audio range (approx. 500 Hz) and its frequency is controlled by a separate envelope via Speed Depth with positive and negative polarity. There are also the usual functions for pitch, modulation, brilliance, a unison switch with four oscillators on one key, portamento and sustain. (Source: amazona)