A digital synthesizer, created and manufactured by the company New England Digital (based in Vermont in the USA). Across various models, the Synclavier was sold over a period of nearly two decades, and its capabilities evolved considerably from the start to the end of the production run.
The Synclavier evolved from a project at Dartmouth College led by professor Jon Appleton, an alumnus of the Columbia-Princeton Electronic Music Center. This involved creating some custom digital hardware that had the capability to perform FM processing, and some additive synthesis, in real time -- a technological advance at the time. Two of Appleton's students, Sydney Alonso and Cameron Jones, formed New England Digital to commercialize some of the work being done in Dartmouth's electrical engineering program. Their first product was a minicomputer called the ABLE, which was introduced in 1975 and sold for a number of non-musical applications.
The next year, New England Digital set about creating the first version of the Synclavier, by combining improved versions of the Dartmouth-developed FM processing hardware, with an ABLE computer for controlling everything. A simple keyboard and a DEC computer terminal formed the computer interfaces; most of the patch editing was done by typing in commands on the computer terminal. This first version was introduced in 1977 and was sold mostly to university music departments and a few studios. As the model evolved, a master keyboard was developed that contained some patch editing controls, consisting mainly of an array of buttons that lit up orange to show which functions were selected, and a value entry rotary encoder. The keyboard with all of the orange buttons become an iconic image of the synth, although this was only a small part of the total hardware complement -- depending on the configuration, the synth included one or more rack-mounted chassis containing the voice processing cards, the ABLE computer, external disk drives, and audio D/A converters and interface hardware.
A Synclavier II model, introduced in 1980, contained many improvements suggested by the consulting performer Denny Jaeger, making the synth's features more musically useful. Throughout the decade, hardware and software improvements introduced new features, notably the ability to perform sampling, process samples by doing Fourier transforms on them, and then use the extracted spectrum to perform resynthesis. The additive synthesis capabilities were improved and some virtual analog features were introduced. By the end of the 1980s, the Synclavier was a true multi-algorithm synth. The user interfaces were also improved; the original simple keyboard was replaced with a sophisticated velocity and aftertouch sensitive one (sourced from Sequential Circuits, which used the same keyboard on its Prophet T8), and the original alphanumeric terminal was first replaced by a DEC VT640 graphics-capable terminal, and then around 1990 by an Apple Macintosh II computer. The synth received considerably more memory and disk storage, as did the embedded ABLE computer. As the system grew, it become popular with well-heeled performers and studios who could afford the high price tag, and many were used for foley and effects work in addition to music.
The synth's recording capability and the availability of cheap disk storage in the late 1980s allowed the synth to be developed to also function as a digital audio workstation, with the ability to record data from external sources as well as its own audio, process and edit tracks, and produce mixdowns. Software developed also allowed the synth hardware to serve some other non-musical purposes, such as signal analysis and some forms of numerical simulation. A notable feature was the Synclavier's on-the-fly audio compression and decompression, a pioneering technology at the time which extended the effective capacity of memory and disk drives.
However, as the 1990s involved, personal computers began to catch up with the processing power of the Synclavier's hardware, and performers found that they could achieve similar capabilities at considerably less expense with soft synths and plug-ins. Sales declined, and New England Digital decided to fold in 1993. Some of the company's assets were sold to Fostex, which used some of the technology to create a series of small hard disk recording systems in the early 2000s. There is no way of estimating how many Synclaviers were produced, since the modularity of the systems meant that they were often combined, split, and reconfigured in various combinations, and many software and hardware revisions were issued over the years. This also makes it difficult to determine the market value of a specific unit, since it is rare to find two that are exactly alike. Keeping a Synclavier running today is an exercise, due to the difficulty in finding either parts or documentation.