> From: wasteking1
>
> I tried your suggested volume test with a long sustained sound
> and the volume slider --it seemed to attenuate in a normal way--
> no early cut out. and i repeat, the non-touch sensitive playing is fine
> I was wondering if each of the 6 voices had a seperate chip(?)
> that dealt with interpereting the volume of the touch sensitivity
> signal that wouldnt affect the normal full signal. [would that
> be the Zx09?] is this touch /volume located in the sample/hold
> area? I have the schematics, but that doesnt really descrbe the
> function of the various parts. [ I also have a dead polaris to
> scavenge chips from if that would be helpful ] sorry, but i have
> no scope, just a meter.

When you say "volume slider", I wonder if you're talking about the Master
Volume. I was talking about the Volume parameter in the Assignable Control
section. The Master Volume manipulates the gain of the single amplifier on
the output board, and has nothing to do with the sample-and-holds or the
individual channels.

All interpretation of touch sensitivity is done inside the CPU; it merely
delivers a single control voltage to each channel for Pitch A, Pitch B,
Width A, Width B, Cutoff and Volume. I can't imagine any mechanism that
would allow these to function normally for non-touch-sensitive sounds, but
function unevenly on touch-sensitive sounds in a way that correlates with
the voice number as opposed to the key number.

With no notes sounding, the voltage on pin 7 of all six Zx03 chips should be
slightly negative; if it's much more negative on the voice in question, then
you've narrowed the problem considerably. This can be tested with a
voltmeter.

--

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