Thursday, September 29, 2011

Micor Inc. Coupland Digital Synthesizer, Synapse 1978

Micor Inc. Coupland Digital Synthesizer advertisement from page 17 in Synapse Magazine May/June (Summer) 1978.

What can I say about the aesthetics of this pre-1978 NAMM advertisement that hasn't already been covered by author Mark Vail in the most excellent book Vintage Synthesizers (page 74):
"While other synthesizer manufacturers printed full-color brochures depicting sexy keyboards clad in a wispy negligee of LEDs and hyperbolic prose, Micor Inc.'s 1978 promo boldly pictured this vaguely nerdy fellow whose glasses were held together by a safety pin."
 That paragraph alone is worth the price of the book. Seriously.

And... it's true. Look closely and you will see the safety pin in the ad photo! Nerd-core at it's finest a la 1978.

Despite what the ad-copy says, the ad doesn't contain any "technical stuff". Nothing. Instead, the marketing peeps had decided to get a head-start on Yamaha's approach to advertising, and make it all about the sound. Smart move if the hard-to-find specs are any indication of what was under the hood. Musicians probably didn't want to read about Fourier harmonics.

The synth's basic specs, or as Mr. Vail puts it - "tentative" specifications - can also be found in the book.
  • 12 waveform generators
  • each generator had 16-voice polyphony
  • 256 Fourier harmonics
  • dual five-stage envelope generators for amplitude and frequency
  • AM and FM inputs
  • variable phase angle
  • velocity-sensitive keyboard, splittable for each waveform generator
  • multiple pedals used for modulation
  • included sequencer - 20 sequences w/editing abilities
Interestingly, even though these basic specs have been available in print for some time, as of this writing the Wikipage for the synth only includes the very technical aspects of the synth.  But, that Wikipage does include some great historical information on this synth that never was.

And this is exactly why I sometimes find researching synthesizers like this frustrating. Even though first-hand spec-sheet documents are known to exist <- that link goes to an eBay page selling a 1978 eight-page promo-catalog for the Coupland Digital Synthesizer - very little actual technical information exists online as far as I can tell.  Of course, I expect someone will pass me a link to the full specs five minutes after this blog post goes live  :)

Luckily, there are a few tidbits of interesting information just a Google search away.

For example, John Moore, who apparently worked with Rick Coupland on the development of the synthesizer (and also looks to have played a role in it's Wikipage) has been active on message boards in the past. I found this 2006 post in a thread that was commenting on the old Synapse magazine that included this ad.

I've included his whole post below because although it includes a some of the same information from the Wikipage, it is written here in a first-hand perspective. I've also included it since I'm darned scared that this information could disappear at some point in the future.
"I worked with my old friend Rick Coupland on the Coupland Digital Synthesizer, especially the conceptualizing in 1973 and 1974 (while we were designing and bilding the infrastructure of the Ramada Inns/Micor hotel reservations system). We independently invented the waveform buffer, a technique to maintain very accurate frequency by having only the most significant bits of the phase counter address the buffer, and a sneaky multiplication circuit that used a weird logarithmic representation ( I think it was log base square-root of 8) for applying the attack/decay/sustain/release to each output channel. This trick was to avoid the very expensive and heat generating multiplier modules on the market at the time.

The original synthesizer used only 8 bit output, but was 16-voice real-time polyphonic and had an 88 key keyboard. We discovered an aliasing effect that was not due to the sample rate or A/D post filtering, and determined it was caused simply by the quantization effects while still in the digital logic (this is an odd concept that needs more explanation than I can give here). We applied dithering of the master clock to make it go away without noticeably affecting otherwise affecting the sound.

The project then gained funding from Micor and was expanded to include modern packaging and a touch sensitive keyboard. It was changed to 12 bit (better IC's were available by then), and the team included a professor of music from UofA.

It was rushed to the trade show (a marketing decision resisted by the technical people), poor Rick was hyped in the marketing literature (against his wishes), and the subsequent difficulties in keeping it working were embarrassing. Both versions used all MSI TTL logic and lots of wire-wrapped prototype boards, which is why it failed at the show.

The second version had a stylish production packaging and a futuristic touch-sensitive console above the force sensing keyboard. Internally was a Texas Instruments 990 mini (or perhaps, by then, the 9900 IC - don't remember) which provided the user interface and did the non-real-time FFT's required to transform from the harmonic-spectrum based voice construction into the time domain waveform buffer. The prototype was shown to several top popular musicians, who were very impressed and wanted to buy the units, but it never made it to production. Rick still has the original prototype. I believe that original 8 bit prototype was given to University of Arizona, where it's fate remains unknown."
Another search result managed to distract me from finishing this blog post for at least a couple of days. Google has been scanning old issues of Billboard magazines (including old ads!) and after finding  this February 28, 1978 Billboard magazine page with a Coupland Synth reference, I immediately got side-tracked and started looking at all the other magazine pages, including all those old music/band ads.

FYI - Foghat really knew how to wear the space gear (last page of this issue).

I also found a small reference to another employee that apparently worked on the Coupland synth. This 2004 Web page for "Let's Soiree with Baron Benham" includes SoirĂ©e special guest Mr. Jim Dilettoso  - "worlds leading authority on UFO's".


Turns out he's done a lot of technical design work over the years including "the design and integration of the world's first real-time digital music synthesizer for Coupland-Micor".

I find it awesome any time I can connect vintage synthesizers with UFOs. :D


Pierre Serné / NetPierre / PatchPierre said...

Great post again, but the title and first paragraph say 'digitial' instead of 'digital'
Keep up the good work anyway! ;)

RetroSynthAds said...

Fixed and fixed! You are now my editor. :)

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