[sdiy] Memorymoog VCO trim

[Barry Klein]

Hi all,
I have been occasionally working on the MM+ I just purchased.
Trying to get 6 tuned oscillators but only get 5.  When I go back to check
usually I find one that is off by >2 digits from 7F.  Is that what would
cause the tune failure or something else?  The oscillator that is off is not
consistantly the same.  I also see a problem where every 6th note does not
play in this test state.  

This is the 3rd MM I have worked on and (as before) the trimpot adjustments
are damn touchy.  So much so that I wouldn't want to even bump one that was
tuned....
Is this due to old trimpots - do new ones make life much easier here?
Anyone tried installing digital pot IC's?
What improvements have you made to your MM's to either make calibration
easier and more stable or even just mods you have made to increase
capabilities?

Barry