[sdiy] modular synth "standards"

[jh.]

> This is a very interesting example you bring up, because PWM
> modulation could just as easily come from an audio source as well as a
> control source.  Or both sources.  As could FM modulation.  But other
> than assuming audio input levels and maybe padding down the input for
> control voltages, I don't see a problem.

I try to say this with other words: As long as all inputs have enough
range of gain or attenuation, the nominal output voltage of modules,
audio or CV, doesn't matter.
Which isn't so far from the situation even in systems that have a
standardized level throughout. For instance, a VCF with "5V" output
level will never have these 5V in its pass band and on its resonant peak
at the same time. It's rather an upper limit for possible output voltages.


> (I believe there are lots of interpolating scanner applications just
> waiting to be discovered.)
>
> Yeah, the scanner is a module that can be used on control voltages
> just as well as audio signals.  Same with a VCA, ring modulator,
> mixer, and a bunch of others.  These modules would be simpler in a
> common-control-and-signal-voltage system and would require input level
> switches or some other compatibility features in a separate-control-
> and-signal-voltage system.

I just picked the scanner because of its DC offset at the output when it's
"abused" as a waveshaper. In fact there are many other modules that
serve as CV processors as well as audio modifiers.

Divide-By-N: Clock divider or Subharmonic generator
Sequencer - stepped waveform generator
Comparator - Threshold switch for keyboard split or PWM modulator
Attack-Decay envelope - gate extractor from audio signals (better than a
  envelope detector)
and so on.
(Haven't found a CV application for my fixed filter bank, however.)

JH.