Archive of the former Yahoo!Groups mailing list: MOTM

Okay, here are some thoughts on modules that change harmonic spacing.

For a modifier, what about something that basically does what a ring
modulator does (but not through simple multiplication obviously)---change
the spacing between harmonics plus or minus---but along a controllable
curve. Is that clear? I'm fumbling for language here. A ring modulator ends
up expanding or contracting the harmonic spacing in a linear way, and
because pitch has an exponential relationship to frequency, we get the weird
metallic non-harmonic sound. What if you could do something similar, but
with "curves" that could be voltage-controllable? As well as the deviation
amount?

Hope that description makes some kind of sense. Due to the nature of a ring
modulator, the higher harmonics in the upper sideband get affected more than
the "closer" ones, and the reverse for the lower sideband. If you could
control the effect along a curve, you could really control the effect and
make it very subtle. At close to exponential I think it would approximate a
pitch shifter. At linear, it would create the upper sideband of a ring mod,
and inverse linear, the lower.

For an additive source module, I guess some kind of high-frequency VCO that
feeds, say, eight "divide-by-N" chains that can divide by large numbers.
Each of these eight chains goes to a VCA and a square-to-sine waveshaper and
are then mixed. These modules could be ganged to add more harmonics off the
same source VCO (or maybe the HF VCO is one module, like a 'driver,' and
there's a second module for the divider banks that can all be fed from one
driver). I realize that this gets to be a lot of circuitry. Probably more
expensive than eight VCOs. But with these things feeding off the same clock
they are locked tight in "tune." Ideally you'd want to be able to specify
the phase of each harmonic, too, but that's getting to be crazy.

Anyway, that's first pass at daydreaming. I wonder what that first module
would sound like. I bet it would be a very weird choruser if used subtly and
mixed back in with the original signal.

Sorry for all these long, dry emails folks. Just trying to keep the mental
juices flowing, get some hopefully new ideas out there on the table.