Digital Keyboards Synergy Preservation Page

This page is devoted to information and projects about one of the most sophisticated synthesizers ever made, the Digital Keyboards Synergy, and its offspring, such as the rare Mulogix Slave 32, and its predecessors, such as the extremely rare Crumar GDS.

If you have a Synergy, it's worth preserving. One tech I talked to estimated that probably less than 100 (of the 700-800 originally made) are still in operation. Slave 32s (essentially a rack-mounted synergy) are much rarer still; only 25-30 were made.

The Synergy has 32 digital oscillators that are allocated to notes as they are played; voices which use more oscillators per note have less polyphony. Each oscillator can play a sine or a triangle wave. The Synergy is primarily known as an additive synthesizer, but you can also do FM on it (although to avoid ticking off Yamaha, Digital Keyboards didn't make a big deal about that feature at the time.) It seems underpowered compared to later additive synths, such as the brilliant Kurzweil K150, which has a bank of 240 oscillators. Yet, the Synergy often sounds just as impressive, if not more. I think that's primarily for four reasons:

• On the Synergy, you actually specify two complete sets of rates and breakpoints for the envelopes, and the Synergy can smoothly interpolate between the two based on, for instance, velocity information. On something like the K150, the velocity has much more limited control. This is much more complex than a simple crossfade.
• On the K150, each partial can be set to non-harmonic frequencies, but each partial is then locked to that frequency. On the Synergy, each partial can have its own independent frequency envelope.
• The envelopes are quite flexible, with up to 16 stages, for both amplitude and frequency. (The Kawai K5000 had only give 5 stage envelopes.)
• Wendy Carlos went nuts on the Synergy, and spent years refining its voice library. Most of her voices only use two or three oscillators, yet they sound incredible. The fact that she tuned them all by ear - i.e. no FFTs or phase vocoders used! - is remarkable.

Synergy Mailing List

The Sounds

Documentation

• Synergy Owner's Manual (1982) (Interesting tidbid from author John Strawn: it was typeset using the PDP-10 in the artificial intelligence laboratory at Stanford.)
• Synergy Manual Addendum, System Ver 3.XX
• Preliminary Operation of the Synergy II Plus w/Computer
• Synergy Host Programmer Reference Manual V 3.XX
• DK-1 Operating System V 2.42 - Installation
• SIA and VRAM Installation
• Synergy Voice Library 2.0 of May '83
• Synergy Cartridge Manual, V Cart 1, Version 3
• Synergy Cartridge Manual, V Cart 6, Version 6

• Wendy Carlos Orchestration, Set WC-123 (italics version)
• Wendy Carlos Orchestration, Set WC-123 (roman version)
• Carlos I, Orch-Plus
• Carlos 2, Bells & Whistles
• Carlos 3, Missing Links

Documentation from other sources:

• Mulogix Synergy Manual Addendum System Ver 3.XX

Magazine appearances: (thanks to Ramiro Turin for sending these scans):

• Synergy II review from Keyboard magazine, by Dominic Milano: Page 1 Page 2
• Synergy II+ review from Keyboard magazine, by Dominic Milano: Page 1 Page 2 Page 3
• Donald Fagan Synergy Ad, from Keyboard magazine
• Questions about the Synergy in Keyboard magazine, April 1986 (answers by Bob Doerschuk)

Circuit Layouts:

• Cartridge board (from Yahoo synergy-synth users group)

The Synergy is based on a digital synthesizer designed by Hal Alles when he was at Bell Labs. This design is extensively documented in two journal papers:

• H.G. Alles, "An Inexpensive Digital Sound Synthesizer," Computer Music Journal, Vol. 3, No. 3, Fall 1979.
• H.G. Alles, "Music Synthesis Using Real Time Digital Techniques," Proceedings of the IEEE, Vol. 68, No. 4, April 1980, pp. 436-449.

Essential Listening

• Wendy Carlos, Digital Moonscapes (read reviews, and Wendy's commentary)
• Wendy Carlos, Beauty and the Beast (read reviews, and Wendy's commentary)
• Wendy Carlos, soundtrack to Tron (read Wendy's commentary)
• Fred Becker, Inner, Stellar
• According to Ramiro Tunin, Christopher Franke used his GDS on the "Thief" Tangerine Dream soundtrack, particularly preset 12 ("Xstrings"), and Klaus Schulz used his GDS exclusively on the rare album "Dig It" on the "Brain" label (Side 1: 1. Death of an Analogue, 2. Weird Caravan, 3. The Looper Isn't a Hooker; Side 2: 1. Synthasy), recorded between May and September in 1980.
• Anyone know of recordings by other artists where it was used?

• Synergy Audio Learning Manual: mp3 of Side A, mp3 of Side B, Pic of side A, Pic of side B, Pic of insert (thanks to Joel Chamberlin for locating the tape and making the scans and the MP3s)

Synergy Links

• Laurie Spiegel Playing 1977 Bell Labs Hal Alles Synth
• Besides my own site, the most extensive Synergy info site I've found is at David Vandenberg's Dragon's Lair Music and Electronics. Click on "Synergy" in the left menu bar. Dave has made several interesting Synergy hardware modifications. Most importantly, he has an EPROM burner and offers Synergy II+ EPROMS for sale.
• Synthony entry on the GDS and the Synergy
• Synergy entry at Synthmuseum
• Synergy entry at Sonicstate
• Synergy entry at Harmony Central
• A Swedish Synergy page!
• A German Synergy page! (Very funny if you run it through Google's translator - you learn that the Synergy is a descendant of research by "Hal of Everything.")
• French pages on the Synergy and the GDS
• Synthtech's Synergy User's Area (alas, hasn't been updated since 1997!), along with a more recent (?) version of the same page. (Documentation link on the former works, but not the latter.)
• John Strawn, who worked on the product specification and manuals for the GDS and the Synergy, founded a company called S Systems, Inc.
• The Synergy makes a brief appearance on a list of microtonal synthesizers
• Brief mention of Synergy engineer Stoney Stockell's contact info (at least as of 1996!) and other Synergy tidbits on Wendy Carlo's page.
• Post on Tuning on modern synths vs. antique early digital synths, which mentions the Synergy (and the fact that there's a whole lot of chips in there)
• The Synergy makes an appearance on a page related to The Moog Cookbook.
• Corley Brigman says he has the Synergy voice editing software, along with a CP/M emulator for MS-DOS
• An extensive Kaypro II Project page, including a comparative list of various Kaypro models
• According to John Strawn, much of the Synergy software was written by S. Jerrold Kaplan, aka Jerry Kaplan. Kaplan's book Startup: A Silicon Valley Adventure detail his adventures with the Go Corporation that occured after his experiences with Crumar and Standford.
• I bought my Synergy from gear hound and manual collector Mark Glinsky. Mark has a second Synergy that he's trying to get working; I believe the DAC card needs a new transistor. If you're interested in buying it once he gets it working, you should get in touch with Mark.

Price Info

Projects

Other projects that might be fun for someone to try:

• Make some modern Windows/Mac software to send voice data to the Synergy over RS-232 (I've been looking for a DB-25 style RS-232 interface for the Mac)
• Make a graphical Synergy voice editor (maybe Java would be good for that?)
• Design and prototype a new replacement DAC card, or a SPDIF interface card for the digital oscillator, to get pristine digital signals out of the machine
• Make an FPGA replacement for the digital oscillator board. The digital oscillator board is around 110 TTL chips - I bet you could fit it in a modern Xilinx or Altera FPGA pretty easily.
• Create a procedure for rack-mounting a Synergy. It looks quite doable; I'd just be hesitant to hack up my only working Synergy.
• It would be feasible to grab some Z-80 simulator code, add code to simulate the front panel interface and the memory-mapped hardware, and actually run the original Synergy operating system on your PC. That would be pretty wild. Some folks are doing this for the Wave PPG 2.3, simulating the 6809 and all its peripheral chips.

The technical documentation for the Synergy is quite detailed, so I think all of the above projects are feasible.

If someone is interested in contributing to such projects, please pop me an e-mail!

Repair

• If he's available, Paul Schreiber (synth1@airmail.net) is probably your best bet. He owns a Synergy, so if you can nail the problem down to a specific board, you can just send him that board (avoiding the cost of shipping the whole thing, which weighs something like 75 pounds). However, Paul's time is mostly taken up by the demands of his fantastic MOTM line. The last time I corresponded with him, he thought he wouldn't be available to do any Synergy repairs until March 2005. But it wouldn't hurt to ask.
• Davidson Electronics wrotes: "We are quite familiar with these units and their architecture. It is best to send the entire unit to us."
• EPR Electronics wrote: "We have the stereo microscopes and surface mount work station needed to repair your [Synergy] unit to a stable and warrantable condition."
• David Vandenberg has created many Synergy modifications. He writes: "If anyone wants to send my their Synergy, I'll be more than happy to try fixing it for them."
• If your keyboard is having issues, check out the Universal Keyboard Upgrade from Virtual Music. They also have assorted other spare Synergy parts. If you're in Europe, they might be able to service your Synergy, as they service a lot of old synths, but I haven't explicitly asked them.