SV: [sdiy] Matrix 6R filter problem

[rkmoore at memphis.edu]

The problem on my unit ended up being a dirty IC socket.  Reseating and
recalibrating made the problem go away completely.  Thanks for the response!

Richard Moore

----- Original Message -----
From: <jays at aracnet.com>
Date: Thursday, July 14, 2005 5:13 pm
Subject: Re: SV: [sdiy] Matrix 6R filter problem

> 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
> > > 
> > > 
> 
>