Hi, I have one of these CEM3340-based monosynths, and it has a problem. It doesn't play in tune, small intervals are fine but over a range of an octave it is nearly a semitone out. I measured the CV from the CV out board and there is a difference of 1V over an octave as there should be, so the problem lies with the synth itself.
Does anyone have a service manual or any more info about how to troubleshoot it further? It is a nice sounding synth with an external filter input, and a MIDI>CV converter too. Would be nice to get it sorted.