Rivera Music Services Engineering Brief and Photo Sheet for Minimoog Modifications, 1980

Rivera Music Services 12-page Engineering Brief and Photo Sheet for Minimoog Modifications from January 3, 1980.

Engineering brief also available as a PDF (4MB).

It's a lot of text, sure, but if you are a Minimoog modding freak or just a modding addict in general it's well worth the read!

These scans all began (that rhymed!) when someone in the Moog Fan Club Facebook group asked if anyone had a close-up photo of the Rivera Music Services (RMS) Chromatic Transpose Minimoog mod. I knew I had a glossy photo sheet of a fully modded RMS Minimoog somewhere that I could get a sweet close-up scan from, so I went digging and in the same sleeve was this engineering brief as well.

And what do you know... it comes with a price sheet. That's some historical gold, right there. And a good reason to scan everything and post. :)

A lot of the content of the engineering brief actually appears in the "RMS Modified Minimoog" brochure that I posted about a year and a half ago. But there's a lot that's different too, including prices!

So, it made sense to do a small comparison between the two docs... and I guess readers of the blog are coming along for the ride.

For a start, the engineering brief contains a whole new first section of mods called "Updates" that RMS said would increase the stability and reliability of a stock Minimoog. This included options for:

• New stabilized oscillator board - $320
• Octave range buffers - $70
• Power supply updates I - $80 and II  - $40
• service check $55

*None* of those are listed in the brochure! Excellent stuff.

The next section in the brief is called "Custom Features", with an array of options that "provide new and unique sounds, functions, and control capabilities". This includes a number of features also found in the brochure I posted earlier. I've included prices for each feature with brochure prices in brackets for comparison:

• Fine tune control:
  Osc 2 - $40  (brochure: $55)
  Osc 3 - $40  (brochure: $55)
  Master tune  - $40  (not in brochure)
• Beat tune  - $105 ($89)
• Ribbon controller with pitch wheel reassignment  - $190 (not in brochure)
• Chromatic transpose with assignment switches  - $185  (brochure: $189)
• Preamp mode - $35 (brochure:  $29.50)
• Distortion - $50 (brochure: $49.50)
• Sync (Osc 2 and 3) - $170 (brochure $174.95)
• Contour (Osc 2 and 3) - $100 (brochure $79.50)
• LFO 4 - $150 / $180 with LED (brochure $149 includes LED)
• Modulation pedal  - $90 (not in brochure)
• Keyboard trigger  - $125 (brochure $129)

The final section in the brief is called the "Interface Capabilities" which added features to allow your Mini to "patches involving other synthesizers, controllers, processors and studio equipment. Again, most of these were available at the time the brochure came out as well:

• External CV assignment - $90 (brochure $129.50)
• Oscillators, filter, and keyboard CV and date outputs - $200 (brochure $124.50)
• V-trig to S-trig conversion cable - $40 (brochure has built this into the Mini as a V-trig input jack  - $49.50)
• Separation of keyboard and console - $250 (not in brochure)

I originally estimated the date of the brochure at 1981, and I was hoping I could compare prices to this engineering brief dated January 1980 to get a better date estimate. I figured if prices in the brochure were higher, then an '81 date would still make sense. If prices were lower, then I'd probably date the brochure a bit earlier... maybe 1979 or even 1978 

But they aren't uniformly more or less when compared! For example, the Fine Tune Control mod costs less in the brief than in the brochure, but Beat Tune mod costs more in the brief than in the brochure. Gah! 

It's also interesting to note a few features from the brief don't appear at all in that brochure - the whole service section, but also the modulation pedal, keyboard separation, and the ribbon controller. The pedal and ribbon controller are just external hardware I believe, no real "modding required", so I can see those being left out just to give more space to actual mods. 

And the separation of the keyboard from the synth is not really a mod - its more a massacre of sorts and probably couldn't really be done by your friendly neighbourhood tech. So that, and all those service mods could probably be excluded from the brochure without too much worry too. 

But still... I like consistency. Maybe some future RMS docs will help me out.