The CS-20M is another of Yamaha’s classic CS-series analog synthesizers of the ’70’s and ’80’s. It is a monophonic analog synthesizer with dual-VCOs that use subtractive synthesis to create superb bass, synth, lead, bubbly-squirty and percussive sounds. It has all the essential components of a classic synth: There is a resonant filter with switchable high, band or low pass filtering with its own ADSR envelope controls. There is an ADSR VCA envelope generator which contains a third oscillator which generates a sine wave to modulate and enhance your sounds. And there is an LFO which can modulate the PWM sweep. Fortunately, the CS-20m features 8 memory locations for patch storage of your favorite or most used sounds.