Rhodes Chroma Polaris

Unfortunately, I don't have access to a scope which makes it difficult to 
diagnose <G>.

--Tom

----Original Message Follows----
From: "Paul D. DeRocco" <pderocco@...>
Reply-To: chromapolaris@yahoogroups.com
To: <chromapolaris@yahoogroups.com>
Subject: RE: [chromapolaris] Another topic...  2 oscillators out of tune.
Date: Fri, 4 Aug 2006 14:48:19 -0700

 > From: Tom Krotchko
 >
 > I purchased a Polaris off the analog list less than a year ago.
 > The thing
 > is in almost perfect shape except that it appears two of the oscillators
 > won't come in tune.  The auto-tune says they are, but they
 > aren't.  You can
 > tell when you play a scale, the 5th and 6th notes will just be off by a
 > couple of tones.
 >
 > Now, some people have told me the problem is the row of caps.  I
 > pulled it
 > apart, saw then, priced them etc.  But I don't want to resolder a
 > bunch of
 > these things (I think there were twelve) and then find out it
 > didn't make a
 > difference.

Do you have access to a scope? You can tell if the problems are in that area
by looking at the outputs of the sample-and-hold buffers (Zx03 and Zx04). If
they have a sawtooth-like modulation on them of more than a few millivolts,
then the voltages on the caps are drooping. This usually means the caps are
leaky, but could also be the 4051 switches, or even the buffers themselves.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...