Sequential Circuits

Sequential Circuits products:
Pro-One, Model 700 programmer, Prophet-5, and Prophet T8

Sequential Circuits Inc. (SCI) was a California-based synthesizer company that was founded in the early 1970s by Dave Smith and sold to Yamaha Corporation in 1987. The company, throughout its lifespan, pioneered many groundbreaking technologies and design principles that are often taken for granted in today's greatly enhanced world of music technology. Sequential Circuits was also pivotal in the planning, design, and support of 1982's groundbreaking music technology, MIDI.

Products and innovations

Sequential's first products were sequencers and programmer devices for third-party synthesizers.

Prophet-5 (1978)

Their first synthesizer, the brainchild of Dave Smith and John Bowen was the very successful Prophet-5, released in 1978. This was the first affordable, fully programmable polyphonic analog synthesizer, and became very popular in the early 1980s. In combining full microprocessor control with low-cost synthesizer module chips made by Solid State Music and later Curtis Electromusic, Sequential was able to make a relatively low-cost keyboard with five voices of polyphony. This revolutionary principle of combining five similar analog voices with easy editing and programming in one case became then the standard for a polyphonic instrument, making it possible to play real chords on a synth as e.g. on a piano. With the addition of patch storage (an innovation brought to reality by Dave Smith with assistance from E-mu's Dave Rossum) the synthesist was able to cycle through many different (up to one-hundred) sounds in a sitting, without having to re-calibrate the instrument for every switch. These were very unexpected developments in the synthesizer industry, especially from a previously unknown company that operated out of a California garage. Dave Smith designed, programmed, and built the Prophet in less than eight months.

Sequential followed up this successful debut with a ten-voice version of the Prophet, Prophet-10 in 1980, coming in a massive dual-manual package with a digital sequencer and the ability to play two different timbres at once. A monophonic version called the Pro-One followed, becoming particularly successful with sales of over 10,000 units.

Prophet 600 (1982)

Sequential was also instrumental in developing MIDI, and, in 1982, introduced the first MIDI synthesizer: the Prophet 600. At the January, 1983 NAMM convention, this instrument successfully communicated with a Roland Jupiter-6 synthesizer in the first public demonstration of the MIDI protocol.

In October 1983 (at the Goodman Music Expo), Hybrid Arts and Robert Moore demonstrated the first personal computer, the Atari 800 (8 bit computer with 48k of memory) communicating to a MIDI keyboard, which was the Prophet 600. The program, MidiTrack, included both a 16 Track, MultiTrack, MIDI Recorder/Sequencer and full graphic user interface (GUI), Synthesizer Programmer/Editor/librarian. All the knobs and switches of the Prophet 600 were displayed on the CRT of the Atari 800, even though the text-only Atari did not display graphics. Robert designed custom fonts to do the graphics and programming was done using a "Light Pen". Over 1,000 "patches" (aka; programs) of the Prophet 600 could be stored on a single floppy disk. Hybrid Arts "MidiMate" (the first MIDI to personal computer interface) connected the Prophet 600 to the Atari 800 computer (no computers offered a MIDI interface). Robert Moore and his partner, Paul Rother designed the MidiMate and also jointly developed the MidiTrack program.

Prophet T8 (1983)

The Prophet-T8 (1983) featured an 76-note wooden keyboard (uneven A to C), and implemented a basic MIDI interface. It had an eight-voice structure that was similar to that of the Prophet 5. The weighted, velocity and aftertouch-sensitive keyboard mechanism was so well-liked that New England Digital adopted it for use in their Synclavier workstations. Dave Smith himself keeps and maintains a T8 unit as the main controller keyboard in his home studio.

Six-trak (1984)

Drumtraks (1984)

The Six-trak (1984) was one of the first multi-timbral synthesizers, equipped with MIDI and an on-board six-track digital sequencer. It was designed as an inexpensive and easily portable 'scratch-pad' machine for trying out arrangements. New iterations of this technology appeared in the Multitrak and MAX keyboards, which also signaled an ill-fated leap into the undeveloped realm of computer-based editing and sequencing. Sequential's relatively unsuccessful experiment in this field set the stage for further financial troubles.

Sequential also released two drum machines: the Drumtraks and the TOM.

Prophet 2002 (1985)

Studio 440 (1986)

In late 1985, the Prophet 2000 sampler was released, along with their last analogue synthesizer, the commercially unsuccessful Split-8.

The Prophet VS vector synthesizer, which was Sequential's only digital synthesizer, came out in early 1986. Boasting a synthesis scheme known as vector synthesis, it combined the revolutionary digital waveform generator and vector joystick to the tried and proven analog Curtis filter, and resulted in a unique instrument with a very distinct sound. It still sees heavy use today despite its reliance on rare custom components with a high failure rate.

The last Sequential Circuits instrument commercially released was the Studio 440. This $5000 unit looked like a drum machine and combined a sampler and a sequencer to make a music composition workstation. This preceded the release of the popular Akai MPC sequencers by several years, which were designed by Roger Linn, a good friend and frequent collaborator of Dave Smith.

In 1987, the company was working on a 16-bit sampler called the Prophet 3000 but went out of business and was bought out by Yamaha. Yamaha then sold the few completed samplers for a very low price. Like most of the Sequential line, this sampler contained features that were far ahead of their time, such as automatic pitch detection, key-mapping, a remote control interface, and facilities for easily looping and trimming sampled sound. Many of these technologies were later included in Yamaha's A-series samplers.

Legacy

Support for Sequential Circuits instruments is now provided by Wine Country, which is run by ex-sequential employee Dave Sesnak. After a short stint at Yamaha, which bore fruit in the form of the SY22 and TG33 vector synthesizers, several members of the Sequential team became part of the Korg R&D department. Dave Smith consulted with Korg at this time, and the powerful and memorable Korg Wavestation synthesizer was born. These two synthesizer designs borrowed certain elements from the Prophet VS, but broke new ground in making full use of the new digital technology that had developed in the years since.

Sequential Circuits products are popular targets for simulation or emulation in software synthesizers, with companies such as Native Instruments and SonicCore offering virtual instruments inspired by the Sequential designs. Various analog modeling synthesizers also include presets to emulate Sequential's signature sounds. For example, the Clavia Nord Lead includes a preset patch bank which contains faithful recreations of the Prophet 5's factory sounds.

Today, Dave Smith operates Dave Smith Instruments, which manufactures, among other things, the Prophet '08, an update of Sequential Circuits' Prophet line; and the Tempest analog drum machine.

Other

The Sequential Circuits logo makes use of the Stop font designed by Aldo Novarese, in addition to a faux-Celtic font used for the model name.

Sequential Circuits products

Model 700 Programmer (1977)

• Model 600 (1974)  –  analog sequencer
• Model 800 (1975)  –  digital sequencer
• Model 700 (1977)  –  programmer
• Prophet-5 (1978):

  The Prophet-5 was Smith's first commercialized product and was first introduced by Sequential Circuits in 1978. The Prophet 5 was a 5-voice analog synthesizer, and groundbreaking in that it was one of the first analog synthesizers to implement patch memory, a feature which scanned the settings of every parameter on the synthesizer and stored it into internal memory. The Prophet-5 was in production from 1978–1984, and sold approximately 8,000 units.

• Fugue (1979)  –  ensemble keyboard consists with polyphonic and solo synth, designed by SCI and built by Siel

Prophet-10 inside

Pro-One (1980)

• Prophet-10 (1980):

  The Prophet-10 was essentially 2 Prophet-5s in one big (and heavy!) enclosure. There were two 5-octave keyboards, allowing the musician to play two different sounds at one time. It also included a polyphonic sequencer module, with its own tape backup module, and up to 10,000 note storage. With the sequencer option, it sold for US $9,000, and less than 1,000 were made.

• Pro-One (1980)
• Pro-FX (1982)  –  the first programmable modular effects units
• Prelude (1982)  –  4 section orchestral synthesizer, manufactured by Siel; a silk screen variation of Orchestra 2 and OR400
• Prophet 600 (1982)  –  the first MIDI synthesizer
• Prophet Remote (1982)  –  remote keyboard for Prophet-5
• Prophet T8 (1983) –  The first "piano action" MIDI synthesizer
• Six-trak (1984) –  The first multi-timbral synthesizer
• Drumtraks (1984)

Split-8

Pro-8 (1985)

• MAX (1984)  –  6 voice synthesizer controlled by external PC
• Multi-Trak (1985)  –  the first multi-timbral synthesizer
• Split-8 / Pro-8 (1985)
• TOM (1985)
• Prophet 2000 (1985)  –  12bit sampler
• Prophet VS (1986)  –  The first vector synthesizer
• Studio 440 (1986)  –  sequencing/sampling drum and music production machines
• Prophet 3000 (1987)  –  Final Sequential Circuits product

External links

• The Birth of the Prophet VS
• The Prophet VS - Retrosound
• The Prophet 600 - Retrosound
• The Pro-One - Retrosound
• Stop font by Aldo Novarese
• Prophet Pro One HQ photos