Yamaha CS01

The silver CS01 is a single-oscillator monosynth with a built-in speaker. It was designed to be a consumer-level keyboard, with a 32-note mini-keybed, but its fat analog sound elevated its status among musicians. The 2-pole VCF is somewhat limited, with resonance being switched either fully on or fully off. The CS01 was followed up in 1984 by the black CS01 II (pictured), which had a better 4-pole filter and a slider for adjusting the amount of resonance.