The CS-40M is a duophonic (2-voice) analog synthesizer with a 44-note 3 1/2 octave (F-C) keyboard and 2 banks of 10 patches that are backed up via a tape interface. It is housed in a wood-finished cabinet with a metal faceplate. All in all, it has 36 knobs, 16 switches, 16 buttons, 12 sliders and 2 wheels. The CS-40M's voice architecture consists of two VCOs, a noise generator, one LFO, two envelope generators (one for the VCA and one for the VCF), and a VCA. Each VCO (Voltage Controlled Oscillator) has a knob to switch between a 6 octave range and another knob for fine tuning. A mixer section adjusts the levels of VCO1 and VCO2. Waveforms are switchable between triangle, sawtooth, and square (pulse). The LFO (Low Frequency Oscillator) is switchable between sine, up-ramp, down-ramp, square, and sample-and-hold. It can easily modulate up into the audio frequencies. The EG-VCO (the envelope generator for the VCO) is a simple AR (Attack Release) envelope. the EG-VCF (the envelope used for the VCF and VCA) is an ADSR (Attack Decay Sustain Release) envelope. The VCF (Voltage Controlled Filter) is a multimode filter, switchable between LP, BP, and HP, with a control for cutoff frequency and resonance (none oscillating). A switch enables and disables the keyboard tracking. The Pitch Wheel is switchable between intervals of a 3rd and a 5th, and the Modulation Wheel has switches to select the VCO and the VCF. There are separate CV(control voltage)/Trigger outputs for each voice and CV inputs for portamento, sustain, brilliance, volume and filter. The CS-40M has high, low, and balanced outputs.
