The Prophet-5 is an analog synthesizer manufactured by the American company Sequential. It was designed by Dave Smith and John Bowen in 1977, who used microprocessors, then a new technology, to create the first polyphonic synthesizer with fully programmable memory. This allowed users to store sounds and recall them instantly rather than having to reprogram them manually; whereas synthesizers had once created unpredictable sounds, the Prophet-5 moved synthesizers to producing "a standard package of familiar sounds".
Between 1978 and 1984, about 6,000 units were produced across three revisions. In 1981, Sequential released a 10-voice, double-keyboard version, the Prophet-10. Sequential introduced new versions in 2020, and it has been emulated in software synthesizers and hardware. The Prophet-5 has been widely used in popular music and film soundtracks.
Development
The Prophet-5 was created in 1977 by Dave Smith and John Bowen at Sequential Circuits. At the time, Smith had a full-time job working with microprocessors, then a new technology. Smith conceived the idea of combining them with synthesizer chips to create a programmable synthesizer; this would allow users to save sounds to memory, rather than having to recreate them manually. He did not pursue the idea, assuming Moog or ARP would design the instrument first. When no instrument emerged, in early 1977, Smith quit his job to work full-time on the idea.
Initially, Smith and Bowen 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.
Production
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 (SSM) chipset with Curtis Electro music Specialties (CEM) 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.
In 1981, Sequential Circuits released the Prophet-10, 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. In 2020, Sequential reissued the Prophet-5 along with a new version of the Prophet-10, the Rev 4.
Features
Early Prophet-5s use voltage-controlled oscillator (VCO), filter and amplifier chips designed by E-mu Systems and manufactured by Solid State Music (SSM). Revision 3 Prophet-5s used Curtis CEM chips manufactured by Curtis Electromusic Specialties. Some owners maintain that SSM oscillators produce a richer timbre. However, the SSM oscillators rendered the instruments unstable and prone to detuning over time. CEM chips have remained more stable.
Unlike its nearest competitor in the 1970s, the Yamaha CS-80, the Prophet-5 has patch memory, allowing users to store sounds rather than having to reprogram them manually. It has a proprietary serial interface that allows the user to play using the Prophet Remote, a sling-style keytar controller; the interface cannot connect the Prophet-5 to other devices. Sequential produced a MIDI interface that could be retrofitted to later Prophet-5 models. Third-party MIDI interfaces have also been offered.
Impact
Before the Prophet-5, synthesizers required users to adjust cables and knobs to change sounds, with no guarantee of exactly recreating a sound. The Prophet-5, with its ability to save sounds to patch memory, facilitated a move from synthesizers creating unpredictable sounds to producing "a standard package of familiar sounds". According to MusicRadar, the Prophet-5 "changed the world – simple as that".