Sequential Circuits Prophet 2000. Courtesy of retrogearshop.com
A sampler introduced by Sequential Circuits in 1985; it was Sequential's first sampler and first digital synthesizer of any kind. At the time of its introduction, all commercially available samplers, including the very expensive Fairlight CMI, did 8-bit sampling; the Prophet 2000 performed 12-bit sampling, making it a milestone model with a clear step up in audio fidelity. A rather basic unit by today's standards, the Prophet 2000 was nonetheless a breakthrough that pointed the way towards 16-bit sampling, which was to become the standard in a few more years.
The 2000 had 8-voice polyphony. The voice architecture was fairly basic, aside from the sampling capability; each voice had a 4-pole low pass VCF, a VCA, two five-segment envelope generators (one dedicated to the VCA and one assignable), and a LFO. A rear panel input allowed connection of either a dynamic-type microphone or a line-level source for sample recording. The VCF and VCA were both analog, implemented with Curtis IC's using the same designs that Sequential had used on preceding analog Prophet models. Patch memory consisted of 12 presets in ROM (which used factory samples also in ROM), plus12 user-writable locations. Patch memory is often misstated as 256 Kbytes; it is actually 256 kilowords (of 12-bit words), or 384 Kb. A memory expansion board was available which doubled memory capacity to 512 kilowords or 768 Kb. An extensive selection of options for setting loop points and loop modes for samples was provided. The synth had built into it a 3-1/2" floppy disk drive for loading and storing samples and patches.
Performance controls consisted of a five-octave, velocity (but not aftertouch) sensitive keyboard, plus conventional pitch and mod wheels. The panel interface was a variation of the one-knob interface; a matrix of parameter names was silkscreened onto the panel, and the user used row and column membrane buttons to select one, then turning the value know to change the value. The row buttons were also used to select patches and presets. Sequential also offered a software patch editor package, which ran on a Macintosh. The keyboard could be split into up to 8 zones, with a sample and patch assigned to each, making the unit sort-of multitimbral. (The "sort of" is because even when the keyboard was split, the unit still only responded to one MIDI channel; there was no way to assign zones or layers to separate channels.)
The Prophet 2000 included a very capable arpeggiator, which almost crossed the line into being a sequencer. Several choices of arpeggiation patterns were provided, including "as played" order. An arpeggiation could be latched, so that it would continue playing after the performer removed his or her hands from the keyboard, and in this mode, additional notes could be added to the arpeggiation by simply pressing the desired keys. The arpeggiator could be sync'ed to MIDI Clock, and it also responded to MIDI Machine Control start, stop and reset commands.
In addition to the keyboard version, Sequential also offered a rack mount version, named the Prophet 2002. The same electronics were also used in the Studio 440 drum machine. The Prophet 2000/2002 remained in production until Sequential went out of business in 1987.