> From: wasteking1
>
> i finally did the memory upgrade on my polaris--- it was very
> easy. but upon doing all sorts of tests to prove its ok i noticed
> that the touch sensitivity was out on voice #1 -- It played
> fine but every sixth note would NOT play with a soft touch...
> just a harder one. I did the voice isolation test and indeed
> voice 1 would not play softly. would this be an issue with a
> chip or connection in Voice #1? or in the keyboard? I had
> cleaned all the contacts, all notes do play.

My guess would be something around the volume sample-and-hold circuit,
causing its output to have a negative bias on it. You could test this by
selecting a steady (non-decaying) sound, and turning the volume parameter
down, and note if that particular voice disappears before the slider gets to
the bottom. I've seen excessive leakage in the 4051 switches (Zx01 or Zx02),
as well as failures in the capacitors (Cx35). Could even be the FET buffer
(Zx03) or the Curtis chip (Zx09), but that's less likely. You could check
the volume control voltage (Zx03B output) with a voltmeter, although a scope
might reveal a negative-going sawtooth wave at the sample-and-hold update
rate, if there's leakage.

--

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