For a 12 bit output, that's 4096 steps in 10.625 volts full scale, or 2.59
mV per step. A semitone is 1V / 12 = 83.33 mV. So that should be 32.17
steps per semitone. In cents the resolution is 3.1 cents.
I think there could be value in having a fixed programmable offset of half
the full scale voltage, for LFO waveforms centered around zero. This could
be tapped from the voltage reference (DACC does not have one onboard),
toggled through an analog switch to an output op amp. To avoid effecting
the accuracy of 0 to 10.625 volt scale output, one could feed that output
directly to the switch, and feed the op amp/offset circuit to the other
input to the switch. Or else simply run the two in parallel without any
software control at all, doubling the number of output jacks, one each for
0-10 and +/-5 volts.
John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.comThe Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com > -----Original Message-----
> From: ComputerVoltageSources@yahoogroups.com
>
>
> > - Output gain & offset pots or fixed?
>
> Fixed at 10.625 volts full scale. 4 steps per semitone at one volt per
> octave 12 bit.
>