Yeah Paul it doesn't seem to do that... if you turn the voice off it goes to negative volts again. But as soon as you hit a note the volume goes to zero and sets there indefinitely I think... weird..

Anyway hopefully can figure the source of it here. The 4051's made no difference. Those caps never leak I'm sure and to have 3 paralell channels? Odd. Maybe I should just hose the whole board with chemtronics..might be a residue issue around the S_H 's

--- In chromapolaris@yahoogroups.com, "Paul D. DeRocco" <pderocco@...> wrote:
>
> > From: Robert Weigel
> >
> > For some reason the other voices sound fine. 3 was the
> > worst. After cleaning things up a bit..now 2 is what three
> > was. Oh and I swapped out the fast 4051 analog switch and op
> > amp that drives the vca in. I was seeing a sawtooth there...
> > leaky S+H I was thinking?
>
> Yup, that's what leakage looks like.
>
> > Also 5 doesn't tune yet I can turn it back on and it sounds
> > ok. it's envelope is strange though. Sustains with that
> > level at zero then turns off w/out it moving. That makes no
> > sense. hmmm. rechecking that..anyway if anyone has seen
> > anything similar... I saw something kinda similar on a siel
> > dk600 where it was that voltages were peaking on the DAC out
> > higher than the reference voltage on 4051's. I adjusted the
> > dac though and...why would it be doing it on three and not
> > the last three?
>
> Not sure what you mean by "Sustains with that level at zero then turns off
> w/out it moving." However, I do recall that the volume envelope has a
> squelch so that when it gets to zero, it is suddenly driven negative, to
> kill any possible bleedthrough. When you do the Volume Offset adjustment
> (LF, A, 9), this squelching is suppressed so that you can hear if there's
> any residual offset. Unless you mean something completely different, I think
> you need to do the Volume Offset adjustment.
>
> --
>
> Ciao, Paul D. DeRocco
> Paul mailto:pderocco@...
>