I know that Keith Emerson has a preset panel or two on his modular system–it’s been mentioned in quite a few interviews and places. I think that you could switch between eight or so patches. Would any engineer types out there care to comment on how something like this would work? Also, is there a schematic out there somewhere for the preset unit? I’m just curious how something like this would work, and it certainly would be handy on a MOTM or Synthesizer.com system.
TIA
It’s basically the same thing as a sequencer.
Instead of having a clock sequentially step through each stage, you manually select the stage. Each stage corresponds to a preset patch. When that stage is selected, it outputs several voltages (one for each parameter of the patch).
Synthesizers.com offers a module that functions as a preset for various voltage levels on other modules:
http://www.synthesizers.com/q143.html
With a number of these q143 modules, I think it would be possible to set up more than one path of patches and preset levels so that you could just switch between your “presets”.
Though at issue is many stock modulars forego voltage control on a number of parameters. A good example is the lack of voltage control on the .com’s ADSR - for better or worse just like on the original moog. One obviously needs voltage control on anything one would want to change.
What usually happened on early preset synths is you’d have little circuit boards with resistors for each pot value. You would switch a board in and it would set the values of each pot. An augmented approach that Yamaha used in the 70s would be to use mini sliders (CS-80) or tiny screwdriver turned potentiometers (GX-1) rather than fixed resistors. That way you could have alterable values in small and not too expensive package.
Correct me if I’m wrong. I think what was going on with the Emerson (originally First Moog Quartet) synth is that the pots on modules went to a switching system. Keith eventually had a bigger system so I’m pretty sure he just did the presets with a subset of his system. You could either connect the pots to make their settings live or bypass them and switch in a board with resistor values replacing the pots. You’d be using this with a fairly stock patch that might have been normalized (i.e. without cables default module to module connections are made internally).
It’s interesting to see how Buchla more or less solved the situation in his new modular (the 200e). He’s got a digital bus for most of the pots (a few apparently aren’t implemented). So you can save all the active pot values and recall their states and send MIDI cc to them. Then he addresses the patch cable issue by building a matrix that’s under computer control. Rather than patch module to module you’d patch anything you’s want to switch to a respective input and output of the 210e Control and Signal Router module. It can connect a source to any connected destination with control over the signal level.
I also heard that some British company built a matrix switcher with storable routings a few years back. I think it was meant for instantly rerouting of multiple pieces of gear to destinations, but obviously it would probably work with modules unless it blocked DC or something.
I believe the Oberheim Matrix 6 family (Matrix 6-R, Matrix 1000), although not patchable, did have digital control of the entire unit which, i believe, used analog oscillators and a Moog-style filter. The 6-R originally had a port that was going to go to a programmer, but to the best of my knowledge, the programmer was never built (or at least, never marketed).
One project PAIA had was an analog monosynth called the Proteus. It, too, had digital control of the synth and would remember the positions of pots. Unfortunately, it was never delivered and people who pre-ordered received their money back.
I’m sure someone will correct me on these synths.