Yamaha CS-20M

This Yamaha CS-20M is fully functional and in good condition. This unit has been serviced and calibrated by Switched On. 

The CS-20M is an analog monophonic synthesizer with patch memory from the late 80s.  It features 2 VCOs, and multi-mode VCF with HP/BP/LP modes, 2 ADSRs, and one LFO.  It also includes some rather unique features that make for a very flexible monosynth.  The LFO wave shape is selectable at the destination rather than the source allowing for different slope shapes to effect each VCO, the VCF, and VCA independantly. Not to mention the LFO does enter audio range making it capable of more aggressive, gritty FM sounds.   One feature found on the higher end CS series synthesizers is an additional sine wave VCO just before the VCA for adding the fundemental frequency back into the final tones mix.  This is very thoughtful feature for adding more low-end or additional clarity with highly modulated/detuned patches or when using the HP/BP filter.

It offers 8 patches of memory though parameters cannot be modified when selected. All patch programming happens in the Panel mode.  The back end features balanced/unbalanced outputs, pedal intputs (Sustain, Portameto, and Volume), CV In/Out, Trigger In/Out, and Tape Memory.

  • Polyphony - Monophonic
  • Oscillators - 2 +1 sine osc. in VCA section
  • LFO - 1
  • Filter - 1 filter with low, band or hi pass; ADSR envelope
  • VCA - 1 ADSR; additional sine wave generator
  • Keyboard - 37 keys
  • Memory - 8 patches
  • Control - CV / Gate
  • Date Produced - 1979