Polyphonic Synthesizer
Four Voice (FVS-1)
Manufacturer	Oberheim Electronics
Dates	1975–79
Price	Four Voice: US$4,295 ($5,690 with programmer) Eight Voice: US$7,790 ($10,185 with programmer)
Technical specifications
Polyphony	4 voice (FVS), 8 voice (EVS)
Timbrality	Multitimbral
Oscillator	2 VCOs per voice with sawtooth or variable-pulse waveforms
LFO	1 with triangle wave
Synthesis type	Analog Subtractive
Filter	Low, band, high, notch filter w/ resonance
Attenuator	2 x ADR envelopes
Aftertouch expression	No
Velocity expression	No
Storage memory	16 patches with PSP-1 programmer
Effects	None
Input/output
Keyboard	49-key
External control	CV/Gate

The Oberheim Polyphonic Synthesizer is a range of analog music synthesizers that was produced from 1975 to 1979 by Oberheim Electronics. It was developed by Tom Oberheim, and was the first production synthesizer capable of playing chords.

Oberheim took the idea and electronics of a Minimoog synthesizer and put them in a small box, making a few changes, and in 1974 introduced the SEM (Synthesizer Expander Module), which became the building block of his polyphonic synths. By strapping two, four, or eight of these SEMs together under keyboard control, he was able to create practical, albeit large, synthesizers that could play two, four, or eight notes simultaneously. The Oberheim Polyphonic Synthesizer was born. Each SEM in an Oberheim Polyphonic generates one voice (or note).

There was an optional Polyphonic Synthesizer Programmer module (PSP-1) for the four- and eight-voice models with 16 memories, which allowed the user to store and recall some sound settings of the SEMs, and you could glide from one note or chord to another using portamento.

The Oberheim Polyphonic was later outdated by a new line of microprocessor-controlled Oberheim synthesizers, beginning with the OB-X. The OB-X was fully programmable and significantly more compact than the Oberheim Polyphonic.

Despite their maintenance cost and rarity, Oberheim Polyphonic Synthesizers are still adored by many musicians today for their characteristic sonic 'thickness' and 'depth' caused in part by the random variance between each SEM module.

Oberheim Dual Manual 8 Voices (factory custom)^[1]
exhibited at Musical Instrument Museum (Phoenix)

• Polyphonic synthesizer

• Two Voice at Vintage Synth Explorer
• Four Voice at Vintage Synth Explorer
• Eight Voice at Vintage Synth Explorer