DMX-1000 Signal Processing Computer. Dean Wallraff, USA 1978



DMX-1000 Signal Processing Computer

 The DMX-1000 was one of the earliest Digital Synthesisers. Essentially it was a dedicated 16 bit audio processing computer designed as an OEM product to be integrated into a existing computer setup – usually a DEC PDP11 microcomputer – where the user would write their own interface and score programmes to run the DMX 1000 from the master computer. The instrument sold for $XX in 1979 putting it beyond the reach of most musicians, however, the DMX was not intended as a mass market product but aimed at electronic and computer music studios (one of the first models being purchased by the University of Milan Cybernetics institute).   The instrument was designed and built by Dean Wallraff previously a programmer at the M.I.T. Experimental Music Studio:

“…I worked there M.I.T.) as a Technical Instructor, mostly doing programming on one of the first visual score editors for music. I composed music using their system, always in non-standard tuning systems. It was slow work, since it took the computer half an hour of calculation to generate a minute’s worth of sound, which was then played back from disk. Some of my music was released on records.

After a year and a half, I decided it was time to leave. The work was getting repetitious, and the pay was low. The big problem was that I would miss the studio’s system, which was the only way I could make music in my non-standard tuning systems. I decided to build my own digital synthesizer, which would let me compose at home, and would generate sound in real time. We moved to New York at this time, into an apartment in an Italian section of Brooklyn…I worked my day job, developing funds-transfer systems for Chase and Citibank, and my night job, designing and building my synthesizer”

dmx-1000 running from a LS1 computer 1982

dmx-1000 running from a LS1 computer 1982

The DMX 1000 was capable of running a varied combination of oscillators, filters and noise generators which could be polyphonically combined and patched (a maximum of 20 simple oscillators with amplitude and frequency control reduced to 14 oscillators with envelope control, or alternatively 6 voices of frequency modulation,  15 first order filter sections, or 8 second order filter sections, or 30  white noise generators) . this made the machine as powerful as the most complex analogue synthesiser on the market at the time but with the additional benefit of being entirely programmable and run from a user generated score in real-time.

To avoid the complexity of the user having to integrate into an existing computer system and write their own software, a complete system,The DMX-1010 was later designed by Wallraff’s Digital Music Systems company which consisted of  a LSI-11 based computer system running score and synthesis software with a floppy disk, CRT terminal, a 61-note keyboard.

DMX-100 and Pod-X

Pod-X was a collection of composition tools designed specifically for the DMX-1000 by the Candadian composer, Barry Truax in 1982 based on his ongoing Pod (POisson Distribution) probability composition model.

“PODX started in 1982 with the acquisition of the DMX-1000 (still working, amazingly enough) – which allowed the flip remark of the “X-rated POD system” to be occasionally uttered. Maybe I could just apply to the Guinness Book of Records for the longest continuously running (and used) computer music system, though it has seen several metamorphoses over that period. And possibly is one of the most productive…”

Despite the DMX-1000′s flexibility it was rapidly killed off by the advent of powerful and much more affordable digital synthesisers such as the Yamaha DX range of FM instruments.

“We sold dozens of the machines during the next few years, to university computer music studios and research organizations. It was the most flexible real-time synthesizer you could buy at the time, and it allowed composers to do things they couldn’t do with any other affordable system. But Yamaha introduced the DX-7 in the mid-80′s, which provided more raw synthesis power (though less flexibility in programming) in a unit that cost a tenth the price of ours. I spent a year or so trying unsuccessfully to raise money to develop a new generation of synthesizers, and then got out of the business.”







The DMX-1000 Signal Processing Computer. Dean Wallraff. Computer Music Journal Vol. 3, No. 4 (Dec., 1979), pp. 44-49

Electronic and Computer Music. By Peter Manning

The Synclavier I & II. Jon Appleton, Sydney Alonso & Cameron Jones. USA, 1977

Late version of the Synclavier II

Late version of the Synclavier II 9600TS system with an Apple Macintosh running a terminal emulator

The Synclavier I was the first commercial digital FM synthesiser and music workstation launched by the New England Digital Corporation (NED) of Norwich, Vermont, USA in 1978. The system was designed by the composer and professor of Digital Electronics at Dartmouth College, Jon Appleton with software programmer, Sydney Alonso and Cameron Jones, a student at the time at Dartmouth School of Engineering.

The origins of the Synclavier began when Cameron Jones and Sydney Alonso started to develop software and hardware for electronic music for John Appleton’s electronic music course at Dartmouth. After graduation Jones and Alonso developed a 16-bit processor card and a new compiler to create their ‘ABLE’  computer, NED’s first product, sold to institutions for data collection applications. The first musical application developed by NED was the ‘Dartmouth Digital Synthesiser’ based around the  ABLE microprocessor which was released as a production model Synclavier I in 1977. The new device was intended as a fully-integrated, high end music production system rather than an instrument and sold for $200,000 to $500,000, way beyond the reach of most musicians and recording studios.

Synclavier 1

Synclavier 1 with the VT100 Computer

The synclavier 1 was an FM synthesis based keyboard-less sound module, and was only programmable via a DEC VT100 computer supplied with the system. This version was quickly replaced by the integrated keyboard Synclavier II in 1979. The model II was a FM/Additive hybrid synthesiser with a 32 track digital sequencer memory and was the first musical device aimed at creating an integrated ‘tapeless studio’. The Syncalvier II was equally expensive echoing the fact that almost all of the components were either sourced from hardware developed for military uses or were custom designed and built by NED themselves. NED designed the system to be as robust as possible, built around their own ABLE computer hardware (as a testament to this durability, NASA chose the ABLE computer to run the onboard systems of the Gallileo space probe which in fourteen years travelled to the edges of the solar system – eight years longer than the original mission plan)

Synclavier-II ORK keyboard

Synclavier-II ORK keyboard

The instrument was controlled by a standard ‘ORK’ on-off keyboard and edited by the same DEC VT100 (later a VT640) computer as well as via a distinctive set of multiple red buttons (the same lights used in B52 bomber aircraft, chosen for durability) and rotary dial that allowed the user to edit straight from the keyboard and get visual feedback on the state of the instrument’s parameters. The keyboard was soon replaced in the new PSMT model by a ‘VPK’ weighted, velocity sensitive manual licensed from Sequential Circuits (the same keyboard as the Prophet T8) that dramatically improved the playability of the instrument.

Synclavier II PSMT

Synclavier II PSMT

The Synclavier II was a 64 voice polyphonic modular digital synthesiser; the user purchased a selection of individual cards for each function making it easy to expand and repair. In 1982 a digital 16 bit sample facility was added that allowed the user to not only sample but re-synthesise samples using FM, making the Synclavier one of the earliest digital samplers (The Fairlight CMI being the first) and in 1984 a direct to disk digital audio recording, sample to (32MB) memory, 200 track sequencer, guitar interface, MIDI and SMPTE capability were included making the Synclavier II an extremely powerful (but very expensive) integrated audio production tool. The instrument became a fixture of high-end music and soundtrack production studios – and is still in use by many. The Synclavier is instantly recognisable on many 1980 film and pop hits; used by artists such as Depeche Mode, Michael Jackson, Laurie Anderson, Herbie Hancock, Sting, Genesis, David Bowie and many other. The Synclavier was particularly championed by Frank Zappa – one of the few artists who privately owned a Synclavier – who used it extensively on many of his works including m Jazz From Hell and  Civilization, Phaze III:

“What I’ve been waiting for ever since I started writing music was a chance to hear what I wrote played back without mistakes and without a bad attitude. The Synclavier solves the problem for me. Most of the writing I’m doing now is not destined for human hands.”

Frank Zappa

Despite it’s popularity in recording studios the Synclavier inevitably succumbed to competition from increasingly powerful and cheaper personal computers, MIDI synthesisers and low cost digital samplers. New England Digital closed it’s doors in 1992, many of the company assets purchased by Fostex for use in hard-disk recording systems. In 1993, A new Synclavier Company was established by ex-NED employees as a support organisation for existing Synclavier customers.

Images of the Synclavier i & II


Yamaha GS1& GS2 Yamaha Corp, Japan, 1981

Yamaha GS1 FM Synthesiser

Yamaha GS1 FM Synthesiser

In 1960 the composer, musician, percussionist and mathematician, John Chowning taught computer-sound synthesis and composition at Stanford University’s Department of Music and developed a version of Max Mathews MUSIC audio programming language, MUSIC II for the PDP8 computer. During this period he began experimenting with high frequency modulation of a sine tone and discovered that by using audio-rate modulation (rather than a lower frequency control-rate LFO type modulation) he could create new tones rich in harmonics. In 1973 Chowning published his research in a paper ‘The Synthesis of Complex Audio Spectra by Means of Frequency Modulation’ which eventually lead to the creation of a new approach to audio synthesis known as ‘Frequency Modulation Synthesis’ or FM Synthesis and to the development of the world’s best selling synthesiser; yamaha’s DX range ( Stanford university is rumoured to have collected more than $20 million in license fees and enabling it rebuild the Computer Research in Music and Acoustics (CCRMA) department).

Yamaha GS1 programmer

Yamaha GS1 external programmer

In 1971 Max Mathews suggested to Chowning that he create a library of recognisable sounds exploiting FM Synthesis’ ability to emulate harmonic rich timbres – brass, percussion, strings and so-on – and to use Stanford University to approach companies for him. After being turned down by several US based companies such as Wurlitzer and Hammond, Chowning and Stanford approached, somewhat desperately, Yamaha in Japan. Yamaha were looking for a new type of electronic instrument having failed to capitalise on the success of the CS80 and GX1 Synthesisers. Yamaha’s Organ Division bought a license for one year; enough to investigate the commercial potential of FM synthesis. The first application of Chownings FM algorithm was in 1975; a monophonic prototype digital synthesiser called MAD. This was soon followed by a polyphonic FM synthesiser prototype released as a production model in 1981 as the Yamaha GS1.

Advert for the GS1 in 1982

Advert for the GS1 in 1982

The GS1 was an expensive (around £12,000 in 1981) FM synthesiser (but not the first FM synthesiser, this was the even more expensive New England Digital Synclavier released in 1978). The arrival of FM synthesis was greeted with confusion and horror by electronic musicians who had just become used to subtractive modular analogue systems. FM synthesis is a radically different approach to sound synthesis; subtractive starts with a complex waveform and subtracts harmonics and tone with filters and modulation to produce the desired timbre whereas Additive Synthesis has no filters but creates varying timbres through the application of combinations of modulators or ‘operators’.

Advert for the GS1 in 1981

Advert for the GS1 in 1981

The GS1 had eight operators arranged as four modulators per voice (two on the GS2 model) – which was a very basic implementation of FM. Despite this, the sound quality of the instrument was very impressive, and, despite the perceived complexity of programming FM (alleviated by yamaha supplying a bank of 500 preset sounds on a data stick) the GS1 found favour amongst the large recording studios who could afford them (only around 100 units were sold).

Yamaha ce20 preset FM synthesiser

Yamaha ce20 preset FM synthesiser

The GS1&2 were superseded in 1982 by the more affordable (£850) mass-market, preset CE20 and CE25 FM keyboards and then a year later in 1983 by the legendary DX7 FM synthesiser.



john m chowning

john m chowning

John M Chowning Biographical notes

Chowning was born in Salem, New Jersey in 1934. Following military service and four years at Wittenberg University, he studied composition in Paris with Nadia Boulanger.  He received the doctorate in composition (DMA) from Stanford University in 1966, where he studied with Leland Smith.  In 1964, with the help of Max Mathews of Bell Telephone Laboratories and David Poole of Stanford University, he set up a computer music program using the computer system of Stanford’s Artificial Intelligence Laboratory. Beginning the same year he began the research that led to the first generalized surround sound localization algorithm.  Chowning discovered the frequency modulation synthesis (FM) algorithm in 1967. This breakthrough in the synthesis of timbres allowed a very simple yet elegant way of creating and controlling time-varying spectra. Inspired by the perceptual research of Jean-Claude Risset, he worked toward turning this discovery into a system of musical importance, using it extensively in his compositions.

In 1973 Stanford University licensed the FM synthesis patent to Yamaha in Japan, leading to the most successful synthesis engine in the history of electronic musical instruments. Chowning was elected to the American Academy of Arts and Sciences in 1988. He was awarded the Honorary Doctor of Music by Wittenberg University in 1990.  The French Ministre de la Culture awarded him the Diplôme d’Officier dans l’Ordre des Arts et Lettres in 1995 and he was awarded the Doctorat Honoris Causa in 2002 by the Université de la Méditerranée and in 2010 by Queen’s University, Belfast. He taught computer-sound synthesis and composition at Stanford University’s Department of Music.  In 1974, with John Grey, James (Andy) Moorer, Loren Rush and Leland Smith, he founded the Center for Computer Research in Music and Acoustics (CCRMA), which remains one of the leading centers for computer music and related research.



‘The Synthesis of Complex Audio Spectra by Means of Frequency Modulation’ Chowning J.  Journal of the Audio Engineering Society.J. Audio Eng. Soc. 21 (7), 526-534. 1973

Con Brio Advanced Digital Synthesizer 100 & 200. Tim Ryan, Alan Danziger, Don Lieberman. USA, 1979


Con Brio ADS 200 1980

The  Con Brio ADS 100 & 200 has become something of a legendary instrument due to it’s phenomenal price – USD$30,000 or about GBP£17,000 in 1980 – and it’s futuristic sci-fi looks. The instrument was designed by three California Institute of Technology students  – Tim Ryan, Alan Danziger, and Don Lieberman in 1979, and was one of the earliest digital synthesisers. The first version  – originally designed to test audio perception in their university research – evolved into the ADS100 and was capable of several types of synthesis modes via it’s 64 oscillators; additive synthesis, phase modulation (Used later in the Casio CZ series.), and frequency modulation (FM synthesis – which brought Con Brio into conflict with Yamaha, owner of Chowning’s FM patent). Despite it’s high price and negligible sales, the ADS 100 did claim some fame when it was later used to generate sound effects for Star Trek: The Motion Picture and Star Trek II: The Wrath of Khan.

Con Brio ADS 100

Con Brio ADS 100


Con Brio ADS 100

The ADS100 was based on 3 MOS 6502 processors (also used in Apple I, II and Commodore 64 computers at the time) and could display sequence patterns and waveform envelopes on a video display. The instrument consisted of a large filing-cabinet sized wooden box for all of the computer peripherals – hard drives, cables and so-on, two detachable 61 note keyboard plus a control panel consisting of numerous coloured lights and a video monitor. The ADS100 was completely hand wired and took over seven months to build only one is known to have been sold – for $30,000 to film composer David Campell, (Beck’s father, who also arranged music for Tori Amos, Elton John, The Rolling Stones, Kiss, Aerosmith) and later acquired by musician and vintage synthesiser collector Brian Kehew.


Con Brio ADS 200

In 1980 the ADS was updated to the ADS 200. The upgrade added another two 6502 processors to make a total of five, new software included a new sequencer that could display musical notation and play four tracks at a time sync-able via CV/Gate interface. The five processors allowed the instrument to run 16 oscillators on each key which multiplied by it’s its sixteen voices capability gave a total of 256 simultaneous oscillators. The smaller ADS200 had a microtonally tunable, split-able keyboard

“‘It was totally configurable in software…we had 16 stage envelope generators for both frequency and amplitude, so it was kind of like the grandfather of the Yamaha DX7. On ours, you could build your own algorithms, using any of all of the 64 oscillators in any position in the algorithm. If you wanted additive, you could add 16 of them together. The phase modulation was similar to what Casio did with their CZ series. You could designate any tuning you wanted and save it. You could split the keyboard, stack sounds, model different parts of the keyboard for different parts of the sound, and save that as an entity – the kind of things that are common now.”

Brian Kehew

1982 saw the release of the  200-R which featured a a 16-track polyphonic sequencer with 80,000 note storage capability editable from the video display. This version was priced at $25,000. Only one was ever built. Like many other High-end, expensive digital synthesisers, the days of the ConBrio ADS were numbered with the arrival of cheaper and available technology – specifically the Yamaha DX7 FM synthesiser (1983) – as well as affordable personal computers running sequencer applications such as Steinberg’s Cubase. After Con Brio’s demise, Danziger and Lieberman have become successful manufacturing semiconductors. Tim Ryan cofounded The Sonus corporation, which later became M-Audio, a leading manufacturer of computer audio interfaces, MIDI controller keyboards, and studio monitor speakers.

Images of the Con Brio ADS 100/200/200R


Vintage Synthesizers by Mark Vail, copyright Miller Freeman, Inc