Great idea Florian. I hadn't thought of that. I'll try as soon as i get home tonight and let you know what happens. Thanks!

Alain.

--- In korg_mono-poly@yahoogroups.com , Florian Anwander <fanwander@...> wrote:
>
> Hello Alain
>
> I could imagine, that the output potentiometer of one (or all) VCOs does
> not "shut" the VCO ouput completely. Though the VCO itself might be not
> audible for us, the Filter on high resonance may react on it.
>
> You may try to disconnect the VCO pcb from the VCF/VCA pcb and check the
> VCF then.
>
> Florian
>
> > Hi everyone! Lately I've noticed that when I "play" the filter in self-resonance with all VCOs off, it doesn't produce as pure a sine wave as before. I can hear what seems to be faint harmonics at different frequencies. And when I look at a spectrum analyzer, I can in fact see some "other" frequencies at very low levels.
> >
> > When I sweep the cutoff, they bounce all over the place. A little like aliasing in a way. Don't worry I've eliminated everything else by take the output straight from the synth. So nothing else can add artifacts.
> >
> > Could it be due to failing capacitors in the filter section Especially those directly connected to the SSM2044
> > Or could it be something else. I've already replaced the SSM2044 with a more recent one and they both exhibit the same behavior.
> >
> > It's a very minor annoyance since it's inaudible when filtering a signal from the VCOs or white noise.
> >
> >
> > Thanks for any suggestions you might have on this. And I'd be curious to know if anyone else has these artifacts on their MP4.
>