Vintage Simmons Drums (UK) Users Group

Having had another look the 3rd 3394 is also missing.

--- In Simmons_Drums@yahoogroups.com, Steve Ridley <spr@s...> wrote:
> 
> > The chips that are missing are marked iC37 & IC38. Can anyone 
verify 
> > that these are curtis chips & what the curtis part number is ? 
> 
> They're Curtis CEM3394s.  There should be one for each tom.  Does 
one of the
> toms work?  There is also a CEM3372, but that's a filter for the 
snare.  
> CEM3394s are not easy to find.  Paul "MOTM" Schreiber keeps most 
Curtis chips, 
> but he's out of 3394s.  You should be able to get the data sheet 
off his site 
> though.
> 
> Do you know why the 3394s were removed?  Before you replace them, 
check the 
> power supply.  Curtis chips are very vulnerable to excess voltage.  
The
> PSU should give +15v, +5v and -6.5v.  I had a PSU go bad in an 
SDS1000
> (cut down SDS9 in a rack), and it took out the Curtis chips and a 
random
> selection of other devices.  Sound familiar?
> 
> I have schematics, but my scanner is dying.  If you're not too far 
away, I
> might consider photocopying and posting them for you...
> 
> 
> Steve