CS01: A small, portable and very basic monophonic synth. Battery powered and with a built-in speaker. Produced 1982; a Mark II version was produced in 1984.
CS-5: Basic monophonic synth with a single VCO and a two-poleVCF. Like most Yamaha monophonic synths of the era, it has Volts/HzCV/Gate inputs for external control. Introduced in 1978 and produced until all production of analog synths ended in 1983.
CS-10: Monophonic synth with a single VCO and a multimode VCF. Produced circa 1977.
CS-15: Monophonic synth with two VCOs and two multimode VCFs. Can operate in a bitimbral mode when used with CV/gate control. Produced 1978-1983.
CS-20m: The "m" series of the CS line were Yamaha's first synths with proper patch memory. The 20m was a two-VCO, one-multimode-VCF monosynth with eight patch memory locations. Produced circa 1980.
CS-30: The top end of Yamaha's monosynth line. Full-featured with two VCOs, two VCFs, two VCAs, three assignable envelope generators, and an 8-step analog sequencer. Physically very large. Produced from 1977 until circa 1980. There was also a slightly smaller CS-30L model, the main difference being that it omitted the sequencer.
CS-40m: Basically a two-voice polyphonic version of the CS-20m, with more patch memory and a cassette interface for patch storage. Produced at the same time as the CS-20m.
CS-50: A scaled-down version of the CS80. Four-voice Polyphonic; lacking the ribbon controller of the CS80, but with an aftertouch sensitive keyboard. It also has the unique color-coded "wheel lever" controls of the CS-80. Produced 1977-1980.
CS-60: Basically a single-layer version of the CS-80. Produced 1977-1980.
CS-70m: One of the last analog synths produced by Yamaha; its production actually continued for a short while after the introduction of the DX7. Six-voice polyphonic with two VCOs, VCFs, and VCAs per voice. Had a provision for a remote keyboard or external sequencer, neither of which was ever produced. Introduced in 1981.
CS-80: High-end polyphonic synth with two layers per voice and some unique VCO and VCF features, plus a keyboard with polyphonic aftertouch (but no MIDI). Beloved sound, but heavy and notorious for not staying in tune. Produced 1976-1981.
GX-1: Massive, expensive organ/synth combo with three manuals, a pedalboard, and organ stops and controls combined into a large console. Required an amplification system which was sold separately. Requires an external programmer to build patches. Many of the circuit designs were re-used in the CS series synths. 50-70 built; few were sold outside of Japan. Produced 1973-1977.
SK-10: Basic string synthesizer with string, brass and organ sections (the organ section is digital). Fully polyphonic. Produced 1979.
SK-20: Adds to the SK-10 architecture a 7-voice polysynth section, with two VCSs and one VCF per voice. Programmability is limited. Produced 1980.
SK-40: Adds to the SK-20 a "solo" monosynth section. Keyboard is splittable and has aftertouch. Produced 1980.
SK-50D: Adds to the SK-40 a dedicated bass organ section and a second manual. Produced 1981.
SS30: Very basic string synth, enclosed in a heavily wood-grained case. Produced 1977.
SY-1: Yamaha's first synth, a single-VCO, single-VCF monosynth. Mostly a preset synth with some editing controls. Produced 1974-1977.
SY-2: Somewhat expanded version of the SY-1. Produced 1975-1977.
SY20: The last analog synth introduced by Yamaha. Single-VCO, single-VCF monosynth with presets and editing capability. Marketed only in Japan. Produced in 1982.