Sequential Circuits Prophet-5
by Brad Coates (www.melmusic.com.au)
In the beginning of 1978, Dave Smith, John Bowen and Barb Smith squeezed into a tiny exhibition booth at Anaheim's Disneyland Hotel and together they formed the newly established Sequential Circuits company. Little did anyone at the time know, they were about to change the keyboard player's world forever with their main display item for the winter NAMM show - the Prophet 5.
Described at the time as "5 Minimoogs in one box", (somewhat incorrectly), the Prophet 5 literally stole the show as the first commercially available and viable polyphonic synthesizer. In actual fact the Yamaha CS80 really deserved the title and was also being demonstrated at the same show. What really created the PRO V's success was its' ability to play 5 notes at once and store all parameters for each patch in memory banks - 40 in all, a thing unheard of in 1978.
The Minimoog comparison was not really valid and probably came about more from its physical appearance rather than its sonic capabilities. More like an ARP than anything Moog produced, the PRO V was similar to an odyssey with its ADSR, 2 tunable & syncable oscillators and dedicated LFO oscillator.
Three successive models were produced during SCI's lifetime - designated Rev. 1, 2 & 3, (short for software revision ). The Rev. 1, although extremely sought after as the earliest version, lacked the later version's tape-dumping abilities and all-important 'tune' button, and whilst being the most unreliable, due to the SSM chips (Solid State Music) the Rev. 1 was also arguably the dirtiest and phattest. At this stage, all Prophets were hand-made, and the tiny company (working from Smiths garage) struggled to keep up with orders. However, only the later Rev. 2's and 3's are able to be MIDI- retrofitted. These were the days when musicians actually PLAYED their synths, so sequencing a prophet in those days was somewhat of a secondary concern, although the company did produce its own dedicated digital poly sequencer (non - MIDI) for the prophet , which was also included in the Prophet-10 (essentially two pro-5's and the sequencer)
Although many think of the Prophet of a strictly analogue machine, in reality, the Prophet was actually an analogue/digital hybrid, as were most of the polys that followed.
The basic features were; 5 voices with 2 oscillators per voice, a 24dB per octave four pole resonant low-pass filter, two ADSR envelope generators, one each for filter and amplifier, White Noise generator, (actually easily the worst-sounding noise on any synth ever- but useful as a modulation source!) Pitch and modulation wheels, (like minimoogs) assignable to either oscillators pitch, pulse width of 2nd oscillator, or filter. Also a whopping 40 user-programmable memories, and - the part that generated all the really complex waveshapes - the poly-mod section, which defined the Prophet flavour more than any other single sound-shaping element.
Of special merit too was the user-programmable tuning mode, which turned the middle row of 12 knobs into tuning knobs for the twelve notes in the octave. This feature allowed the user to experiment with alternative tunings, and Wendy Carlos (Switched-on Bach) was among those espousing the virtues of programmable tuning scales, as companies like DSK (Synergy) and Yamaha started including user-scales in later 80's synth designs.
The keyboard was a 5 octave Pratt-Reid note on/note off affair with no touch response. Selling in Australia in '79 for around $5,000 -$6,000, the Prophet came in several thousand dollars cheaper than Yamaha's CS80, and virtually single-handedly destroyed the string/brass machine market, the only other contenders when it came to polyphonic capability. (Oberheim SEM based polyphonic systems excepted.)
Unfortunately, Sequential Circuits was doomed to become yet another synth-manufacturer- casualty, and their R&D and other concerns were taken over by Yamaha in the late 80,s. One of the last great synths they made was the Vector-Synthesis Prophet from which certain design elements were 'pinched' for the now-classic Korg Wavestation, and other TG series Yamaha synths...
Users at the time were Tears for Fears ('Shout" was almost completely inspired by the Prophet-5) Peter Gabriel, Japan (Check out the 'Tin Drum' album, and 'Ghosts' in particular) Spandau Ballet, Blancmange, Tangerine Dream, Larry Fast , Michael Boddicker, Wendy Carlos ('Tron' soundtrack) and a host of other 'Euro-Synth' and Rock outfits of the day.
Pro V's still occasionally turn up on the second hand market, but beware - SSM chips for Rev 1 & 2 are simply no longer available and Wine Country the only real supplier of Curtis chips recently ran out of their supply and are no longer able to provide spares. Dealers in second hand synths now buy dead Pro V's for spare parts only. Rule of thumb when buying privately, if it's not working absolutely perfectly, DON'T buy it !! Should you require use of a Pro V for recording, hire units are available from Billy Hydes Stage Systems (Rev ) 03) 9415 8877 and Melbourne Music Centre's Unique Audio Hire 03) 9578 2426.
Originally published in Australian Musician Magazine, 1998.
Used here with permission from the author.