>How greatly does this affect the pitch of the voice ...
It detunes four of the six voices by a different amount. It works by
controlling the unison detune circuit and not by any individual detune
of a single VCO. I didn't actually measure the amount of detune, I did
it by ear alone, but its more likely to be measured in cents rather than
semitones. I guess maximum deviation is around half a semitone. Its
actually quite tricky to measure individual detune, you'll need to tap
into the separate voice outputs.
Individual detune of each VCO is a worthy mod, but rather heavy in
additional pots. I wanted one simple detune pot. Its easy to use and
doesn't affect any other key assign modes. Its also very easy to do.
It is possible to use the unison detune circuit to control each voice,
and this may be a good way to add significant detunes if you can spare
the pots.
Cheers,
Tony