A polyphonic analog synthesizer released in 1976. The Yamaha CS-80 is considered to be Japan's first great synthesizer. It supports true 8-voice polyphony (with two independent synthesizer layers per voice) as well as a primitive (sound) settings memory based on a bank of micropotentiometers (rather than the digital programmable presets the Prophet 5 would have soon after), and a very complete performer expression features, such as a layered keyboard that was both velocity-sensitive (like a piano's) and pressure-sensitive ('after-touch') but unlike most modern keyboards the aftertouch could be applied to individual voices rather than in common, and a ribbon controller allowing for polyphonic pitch-bends and glissandos. There are 22 preset sounds (6 user) selected from bright and ugly colored buttons above the keyboard.
Production of the instrument ceased in 1980. Vying with the Prophet 5, and OB-X polysynths, the CS80 is regularly described as the pre-eminent polyphonic analog synthesizer, and commands amongst the highest prices of any polyphonic synthesizer.