Hi Jimmy ! spaceanimals a \ufffdcrit : > > A friend of mine built a radio shack synth. It uses one osc and > something to divide it into 10 frequencies. How many ocs does a > polyphonic synth have, and how do you get them to different > pitches--I'm guessing there aren't 61 osc. > They have as many "oscillators" (or pairs of oscillators as in your AN1x) as the maximum polyphony. 10 notes maximum allowed = 20 oscillators. The internal software (all polyphonic synths or at least 99%) allows dynamically one note (pitch and velocity) to one free oscillator until all of them are busy. Then, depending on the synth the lower note, the upper, the first or the last is omitted or cancelled. On some instruments you can choose how the soft reacts to polyphony overflow. The Radio Shack synth is one of the 1% based on an upper octave generator and a frequency divider for lower notes. This is very easy with square waves only, because you can easily do that with basic logic flip flop or binary counters : divided by 2 = one octave lower. But famous early Korg polyphonic synths like this one : http://www.vintagesynth.com/korg/ps3100.php and its bigger brothers were based on the same system. One another hand 99% of electronic organs were based on frequency division, because they mostly work with square waves and the filtering is fixed and much more simpler than in a synth. Today's organs are mostly based on samples, as digital pianos, including.... Hammond or other vintage organs samples ! Hope that it helps. Cheers. J.F. > > > Jim > >
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Re: [AN1x] ot analog synths
2012-02-01 by Jeff