On Mon, 1 Nov 1999, Dave Bradley wrote:
> Tell me more! Top octave / divide down generated stuff? How do you solve the
> problem of detuned oscillators, where the beating frequencies don't remain
> constant across the audio range?
Octave divider(s), yes. ∗But∗ ...programmed in uC code. I can make
coarse or fine changes in pitch by altering the period registers. Based on
a MIDI or CV value, the "proper" detuning will be applied. A knob/CV can
adjust the detuning away from a basic, and another knob/CV can specify the
duty cycle. (typically 10% to 70%)
Someone is bound to ask, so I'll state it here. It is possible to
generate 8-voice polyphonic pulse waveforms on a fast uC. In fact I
programmed a 12-note "+octave 3" (A=440) divider on a uC that was ten
times slower than the part I have in mind for this.
The tricker uC to program is the voltage-controlled pulse delay line to
achieve a chorusing effect. If the tone generating uC is savvy enough,
this one is not needed.
There won't be any filters in the module I'm imagining. Thats what the
4xx's are for.
--Crow
/∗∗/