Thu Jan 13 16:33:57 EST 2011
Synth requirements revisited
These are mostly about complexity and price.
- No manual calibration (trimpots, hand matching components)
- No obsolete or near-obsolete components
- Digital tuning, either direct or using feedback control
- Minimal discrete component count
Some early assumptions overturned:
- Not allowing analog CV modulation is a bad idea.
While it might be a nice way to get to an incrementally working
design, you really want to leave open audio-rate modulation of the
filter and oscillator frequencies. It's virtually for free on the
analog side, once you have the exp converter working.
Problem is calibration though: feedback calib is probably simple,
but analog calib costs something.
- On-line control might not be so essential for anything else than
the oscillators. If it's good enough for the prophet 5 and the
mopho, 7 bits should be plenty for my little project too. Of course, using the
filter as an oscillator does up its requirements.
EDIT: mopho filter cutoff does respond to more than 7 bits, and I
believe so does the Prophet knob control.