Oberheim OB-X

Oberheim OB-X is a polyphonic analog synth produced by Oberheim from about 1978 to 1984. It was Oberheim’s first fully integrated polyphonic synth, with all parameters for all voices under one set of patch controls, as opposed to the piecewise approach taken with the Four Voice. The voice architecture was fairly conventional, with two VCOs (one of which could be synced to the other), a traditional Oberheim two-pole lowpass VCF, a VCA with an ADSR envelope generator, and one LFO. It had patch memory with 32 memory locations, and a cassette interface for external patch storage. Curtis integrated circuits were used extensively, another departure from the Four Voice.

Oberheim OB-X Price Tracker

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The base configuration came from the factory with four voices, but it could be expanded in the field to 6 or 8 voices by adding voice cards. It had two vertical levers, rather close together, for the pitch wheel and mod wheel functions. Near these were a set of switches for shifting the patch up or down one octave, and for controlling the pitch wheel range. The keyboard had a generous five-octave span but was not velocity or aftertouch sensitive. It had no MIDI, being that MIDI had not been invented yet in 1978, although Kenton does offer a retrofit.

Oberheim OB-X Classic Analog Synthesizer Sounds (1979)
(c) 2014 vintage synthesizer demo by RetroSound supported by UVI:

Oberheim OB-X Classic Analog Synthesizer Sounds (1979)


Synth player Wayne Famous (McNatt), of the early-1980s New Wave band The Producers, was noted for attaching a guitar strap to an Oberheim OB-X and wearing it around his neck, in the manner of a keytar. Years of performing while wearing the heavy OB-X caused him back problems later in life.

The OB-SX was a preset synth that used the same electronics as the OB-X. At one point, Oberheim offered a service wherein a performer could send to the factory a data cassette containing OB-X patches, and the factory would build an OB-SX with these patches burned into its ROM.

Oberheim OB-X Details

Dates Manafactured1979 – 1981
Voices4, 6 or 8 voices
Oscillators2 VCOs per voice
Synthesis typeAnalog Subtractive
Filter12dB per octave resonant low-pass
Storage memory32 patches


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[block] Release Date: [field Release] [/block] [block] Keys: [field Keys] [/block] Manufactured by Sequential Circuits Dates 1978-1984 Price US$4495 (Rev 1, Rev 2); US$3995 (Rev 3) Technical specifications Polyphony 5 voices Timbrality Monotimbral Oscillator 2 VCOs per voice LFO 1 Synthesis type Analog Subtractive Analog Frequency modulation via Poly-Mod Filter 24 dB/octave resonant low-pass Attenuator 2 x ADSR; one for VCF, one for VCA Aftertouch No Velocity sensitive No Memory 40 patches (120 patches on later units) Effects None Input/output Keyboard 61 keys Left-hand control Pitch & modulation wheels External control CV/Gate Optional factory MIDI kit for later Rev 3 units