[sdiy] Details of the basic additive/FM voice Synclavier oscillators?

[karl dalen]

Check out the CMI III voice card quite complex i get the impression
they used a time multiplexed variable rate design. At least CMI
always marketed it as a variable sample rate.

> Scott Nordlund <gsn10 at hotmail.com>
> There's a real shortage of good documentation, but I've
> looked into it a bit. That diagram should be pretty
> descriptive. You'll notice that it's variable sample rate
> and uses a hardware multiplier for modulator scaling. The
> carrier waveform is user definable, 24 harmonics. The end
> result is horrendously inefficient (separate expensive
> hardware for each voice) but doesn't suffer from aliasing or
> quantization noise due to amplitude scaling, or even loss of
> envelope resolution at low voice amplitudes. As far as I can
> tell, the design dates back to the Dartmouth Digital
> Synthesizer (circa 1974). So although Yamaha's eventual
> optimizations were far more advanced (the DX7 did it all one
> one ASIC with a log-sine ROM, exponential ROM, accumulator
> and 96 stage shift register), the Synclavier is a descendant
> of one of the first hardware implementations of FM.