I’m pretty new to the analog snyth world. I’ve an old Realistic MG-1 which where produced by moog in the 80’s. I recently had it cleaned up and re-soldered where necessary. All of the sliders and knobs work as they should, but there is one problem. If hold down a note, I can get the two oscillators and polyphony all in tune. But when I play the same note and octave up, it’s quite sharp and all three tone sources are out of tune with each other. The same happens when I go an octave down but it goes flat instead of sharp. One thing I have noticed is that when I hold one note and build a chord around it, all the notes play perfectly in tune.
any ideas about how to calibrate it?
I have already tried messing with the rear screwdriver pots with no luck.
any help is appreciated 