It’s hard to resist another seminal classic from Cherry Audio, says Roland Schmidt, but at a bargain price of zero, are they selling themselves short?

When Tom Oberheim launched his company in 1969, he probably didn’t realise the influence his designs would have. His initial products were based around effects processing, followed swiftly by one of the first digital sequencers. But it was the appearance of the Synthesizer Expander Module (SEM) in 1974 that captured the imagination of musicians and≈synthesists, which continues to this day.

The one and OB

The SEM was (and is) a monophonic synth voice, replete with two oscillators, variable-state filter, envelopes and LFOs. It was designed to act as a voice-partner for the Oberheim DS-2 sequencer, before Tom had the idea of placing two, four and even eight SEMs in a keyboard construct, creating the 2-voice, 4-voice and 8-voice synthesisers. After several years in the production wilderness, SEMs were brought back to life, with a limited number of hand-built reissues being manufactured during the years after 2009. With the exorbitant cost of both the vintage and reissued models, the appeal of software has never been greater, especially at a zero price point.