A monophonic analog synth produced by Oberheim, beginning in 1978. The OB-1 basically contained the guts of a SEM and had the same sonic capabilities (two VCOs, one multimode VCF, two envelope generators, one LFO), integrated into a case with a three-octave non-velocity or aftertouch keyboard. Notably, it had patch memory with eight locations, adapted from the patch memory module made for the Four Voice. A noted feature was the "flipper" pitch wheel control, which pivoted from its left end.
There were at least two and possibly three versions of the OB-1. The original version had a black case and white knobs. Some of the knobs had black centers; these indicated which parameters were memorized by the patch memory. In 1979, Oberheim redesigned the panel to match that of the just-introduced OB-X, with graphics on a dark gray background, and black knobs; this was advertised at some point as the "OB-1A" model, although that terminology did not appear on the synth itself. It appears that at some point in the production run of this model, some of the SEM circuitry was replaced by Curtis-based circuitry borrowed from the OB-X. It is unclear when production of this model ended, or how many were built.
A persistent rumor states that Star Wars producer George Lucas named the character Obi-Wan Kenobe after an OB-1 that he used in scoring an earlier film, THX-1138. This seems improbable because Star Wars was released in 1977, and the OB-1 did not go into production until 1978.