Origins
The Prophet-10 has a complex and somewhat paradoxical history: it was both Sequential Circuits' first synthesizer design and one of its last successful products. In 1978, Dave Smith and John Bowen conceived the Prophet-10 as a ten-voice polyphonic synthesizer while working on a Minimoog programmer and early digital sequencer. Their vision included a five-octave keyboard, genuine polyphony, powerful polyphonic modulation, complete parameter memory storage, and a punchy Minimoog-inspired sound. However, the original design proved hopelessly unreliable — severe heat buildup within the case caused constant tuning instability, with the instrument drifting out of tune within minutes. This forced Smith and Bowen to make a drastic decision: eliminate half the electronics and create the five-voice Prophet-5 instead. Almost all of the early ten-voice units were recalled and converted to five-voice instruments, now known as Rev 1 Prophet-5s.
The Prophet-10 was eventually reintroduced in 1980-1981 as a dual-manual instrument, after Sequential had refined the technology through the successful Prophet-5 production run. This later Prophet-10 represented more than simply two Prophet-5s in a box — it offered flexible voice allocation modes and could function as two independent synthesizers simultaneously, with individual manual transposition and four keyboard assignment modes including the ability to layer both manuals.
Design & Technology
The production Prophet-10 featured ten voices of polyphony with two voltage-controlled oscillators per voice, yielding twenty oscillators total. Each voice included a low-pass resonant filter with ADSR envelope, poly-mod section, noise generator, and a single LFO with adjustable rate. The instrument stored 32 patches in internal memory and included a sophisticated polyphonic sequencer capable of storing between 4,000 and 10,200 notes depending on the revision.
Three distinct hardware revisions were produced. Rev 1 units (approximately 300 manufactured in the early 1980s) featured unreliable Exatron "wafer" drives for patch backup that proved incompatible between machines and suffered memory problems requiring a factory "ugly mod" recall. Rev 2 and Rev 3 units replaced the failed Exatron drives with more reliable Braemer micro-cassette drives and increased sequencer capacity to 10,200 events. Only two prototype SSM-based Prophet-10s are known to exist, and neither functions. All production dual-manual units utilized Curtis Electronics Manufacturing (CEM) chips — the same architecture as Prophet-5 Rev 3 and later — rather than the earlier Solid State Microdevices (SSM) chips. The CEM-based instruments offered greater tuning stability, more consistency between voices, and less distortion than their SSM predecessors, though some audiophiles consider the CEM sound marginally brighter and less organic.
The Rev 2 and Rev 3 dual-manual configuration featured two 61-key keyboards (122 keys total) in a massive case that required multiple crew members to transport, especially when housed in its Anvil flight case. Control was via CV/Gate, though MIDI retrofits became common and are now recommended for modern integration.
Impact & Legacy
Despite its troubled production history and limited manufacturing run, the Prophet-10 achieved iconic status among film composers and progressive rock keyboardists who required expansive polyphonic capabilities. Brad Fiedel used a Prophet-10 to record the soundtrack for *The Terminator* (1984), while John Carpenter employed both the Prophet-5 and Prophet-10 extensively for his film scores. Vangelis used the Prophet-10 on the *Blade Runner* (1982) soundtrack. Stevie Wonder recorded with a Prophet-10 on his 1980 album *Hotter Than July*. Patrick Gleeson used two Rev 1 Prophet-10s on *Rainbow Delta* (recorded late 1978 through spring 1979). Other notable users included Hall & Oates, Japan, Devo, Tears for Fears, Tony Banks, Phil Collins, Rick Wakeman, Duran Duran, Geoff Downes, Talking Heads, Pink Floyd, The Cars, and Kraftwerk.
The Prophet-10's tuning stability issues and massive physical footprint limited its commercial success compared to the Prophet-5, which sold over 6,000 units. The dual-manual Prophet-10 remained one of the most desirable and rare analog synthesizers of all time, commanding premium prices on the vintage market.
In September 2020, Sequential (the company founded by Dave Smith after reacquiring the brand) introduced a modern reissue of the Prophet-10. This new instrument embodies all three original Prophet-5 revisions through genuine Curtis analog VCOs and filters, including new 2140 low-pass filters designed by Dave Rossum (who designed the original 2040 filters used in Rev 1 and Rev 2). Unlike the original dual-manual design, the 2020 Prophet-10 features a single five-octave semi-weighted Fatar keyboard with velocity sensitivity and aftertouch — capabilities the original never possessed. The modern version includes USB, MIDI, gate and CV inputs/outputs, housed in a steel and hand-oiled black walnut body, with a US MAP of $4,299.