[sdiy] Matrix 6R filter problem

[rkmoore at memphis.edu]

Hi everyone,

Today I got my hands on a Matrix 6R (for $130!) that seems to be in good
order, except one voice has a problem.  The filter sounds like it has a
higher cutoff and resonance setting than the other voices on most
patches.  I have briefly combed the internet and learned that this synth
uses the CEM3396 osc/filter IC (any left Paul?).  The voice DOES play,
and the oscillator sounds fine, but the filter sounds wider open than
the others.  I tried the 'calibrate' command, but didn't notice a
difference afterwards.  Has anyone dealt with an M6R in similar shape? 
Also, is it possible to simply de-assign the bad voice and use the other
5?  I haven't had the machine open yet, so I haven't tried moving IC's
around to see if the problem moves (hope they're socketed!).  Any
responses will be appreciated.  I've got a 48 hour return period from
the store.

Thanks,

Richard Moore