Hello,
I just got a Sequential MultiTrak that needs a little love. There are a few voices that are out of tune. If I set the pitch wheel just right, those voices go in tune, but it shifts other voices to be out of tune. Using the tune function doesn’t work. If I shift the coarse tuning up an octave, it shifts other voices to be out of tune. The master tune pot is jumpy and isn’t functioning properly. The pitch wheel was jumpy, until I replaced the 4051 it goes to. Now it functions for the most part, but is steppy.
I’ve switched voice chips around and got no change. I switched out a 4051 on one of the bad voices and got no change. I did switch out a couple of caps that are around the DAC pins that deal with the pitch wheel and master tune. No change. I’m starting to think it may be the DAC or Buffer, Inverter, or Comparitor.
Any thoughts? I appreciate any help that can be given.