The Prophet-5 was created in 1977 by Dave Smith and John Bowen at Sequential Circuits, who aimed to create the first polyphonic synthesizer with patch memory. Initially, they developed the Prophet-10, a synthesizer with ten voices of polyphony; however, it was unstable and quickly overheated, creating tuning problems. Smith and Bowen removed half the electronics, reducing the voices to five and creating the Prophet-5. Smith demonstrated the Prophet-5 at NAMM in January 1978 and shipped the first models later that year. Unlike its nearest competitor, the Yamaha CS-80, the Prophet-5 had patch memory, allowing users to store sounds rather than having to reprogram them manually. Three versions were built between 1978 and 1984. The first, Revision 1, was hand-assembled and produced quickly to generate initial revenue; only 182 were made. Revision 2 was mass-produced in quantities over 1,000; this model was more robust, added cassette patch storage, and replaced the koa wood casing with walnut. Revision 3 replaced the Solid State Music chipset with Curtis Electromusic Specialties chips, necessitating a major redesign. According to Sound on Sound, Revision 3 "remained impressive and pleasant to play, but was slightly cold and featureless by comparison to earlier models". In all, approximately 6,000 Prophet-5 synthesizers were produced.
Prophet-10
In 1981, Sequential Circuits finally released the Prophet-10 synthesizer, featuring 10 voices, 20 oscillators, and a double manual keyboard. Like the Prophet-5 Revision 3, it uses CEM chips. The first Prophet-10s used an Exatron Stringy Floppy drive for saving patches and storing sequencer data. Sequential later moved to a Braemar tape drive, which was more reliable and could store about four times as many sequencer events.
Early Prophet-5s used voltage-controlled oscillator, filter and amplifier chips designed by E-mu Systems and manufactured by Solid State Music. Revision 3 Prophet-5s used Curtis CEM chips manufactured by Curtis Electromusic Specialties. Some owners maintain that SSM oscillators produced a richer timbre. However, the SSM oscillators rendered the instruments unstable and prone to detuning over time. CEM chips have remained more stable. The Prophet-5 uses five voices of polyphony. Each voice is assigned two VCOs. Both oscillators can generate sawtooth waves and square waves, and the second oscillator can also generate a triangle. The oscillators can be played in sync, or in "Poly-Mod", with oscillator B and the filter ADSR envelope modulating the frequency, pulse width, and filter of oscillator A. A dedicated low-frequency oscillator is also present to modulate the pulse width and/or pitch of oscillators A and B and filter cutoff frequency. The Prophet-5 uses a 4-pole resonant low-pass filter. The filter has a dedicated ADSR envelope and keyboard tracking.
Successors
developed a softsynth version of the Prophet 5, the Prophet V. Prophet V also includes a recreation of the Prophet VS, a synthesizer manufactured by Sequential Circuits in 1986. Elements of the two synthesizers can be combined in a "hybrid" mode. The softsynth closely recreates the layout of the original analog synthesizer, though there were some differences in programming, notably through some restrictions on the envelope generator. In January 2015, Smith announced that Yamaha's president, Takuya Nakata, had granted him rights to the Sequential brand, which he had been unable to use following the company's acquisition. The release of the name coincided with Smith's debut of the Prophet-6, a new synthesizer based on the Prophet-5 with additional features.
