SV: [sdiy] Matrix 6R filter problem

[jays at aracnet.com]

All the M6Rs and Matrix12 and Xpanders I have all have sockets. It has been a big problem for me. I had a M6 once which the uC fell out of the socket and was rattling around inside the unit.

I would reseat the one chip that is on the bad voice and then re-cal before I did anything else. If that didn't fix it then I would swap chips and see if the problem moves. Always re-cal before testing too. Another thing is be careful of the sockets. They use cheap sockets and I've pulled the pins out of them when swapping chips.

These units are getting to the point (age wise) where replacing the caps (electros and tantilums (sp?)) wouldn't be bad either. I haven't used my M12 in a while since it has gotten noisy from bad caps and the legend overlay has shrunk to the point there the keys are rubbing and sticking.

Jay S.

karl dalen wrote:

> If the filter cuts in 24 db but are only upp a bit in freq check the
> filter capps (4 of them)and  check the DAC CV at VCF CV pin input.
> If these are OK then something are wrong with the IC!
> 
> 130 are great price!
> 
> REG
> KD
>  
> --- rkmoore at memphis.edu skrev:
> 
> > 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
> > 
> >