I figured I won’t post this under a new topic because it’s likely this doesn’t have anything to do with the ModyPoly upgrade, but just in case, I wanted to check:
I recently got a problem with my ModyPoly-fitted Polysix. The first of the six voices started taking longer to auto-calibrate to correct pitch after startup (the other five voices are fine – and after warming up for 20 minutes the whole unit remains in perfect tune).
Could this have anything to do with ModyPoly key assigner chip / or do you have any idea what could be causing something like this for a single voice? After powering the synth on, the broken voice starts up very high (a couple of octaves or so) and then immediately starts steadily lowering towards the right pitch.
By observing the leds, I know exactly which voice it is – I checked with a multimeter that the close-by resistors for that voice give the same values as the other voices. I also tried swapping the filter/adsr -chips in question, from other voices, but this had no effect.