Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

Hey, any news ?

--- In PolySix@yahoogroups.com, Niels Ott <niels.ott@...> wrote:
>
> Hi gil,
>
> the SSM∗ are OK, I checked them. I had a nice day with the
oscilloscope
> and found out: The output of the signal generator board is already
bad.
>
> Then I replaced two opamps 4558 which I suspected to be the problem
but
> it didn't help. Still 0V out instead if the signal on oszillator 2
(VCO
> 1 (sic)).
>
> Next suspect was the CMOS switch which I replaced by a similar
type. But
> Somehow it wasn't similar enough, so I got -9V in the output now,
which
> is definitely not good.
>
> I'll keep on soldering. ;-)
>
> Best,
>
> Niels
>
>
> gil_we schrieb:
> > Did you switch SSM2056 and SSM2044 between voices to see if it
may
> > lay there ?
> >
> >
> > --- In PolySix@yahoogroups.com, Niels Ott <niels.ott@> wrote:
> >> Hello there,
> >>
> >> my Trident MK2 is defective.
> >>
> >> Symptom: VCO 1 is defective for one voice.
> >>
> >> Up to now I was able to found out: Input 1 of IC704 (4x CMOS
> > switch) on
> >> KLM-379 doesn't get the VCO signal on voice 7. On all others it
> > does.
> >> There are some oddities with op amp IC707 but I'm not yet sure.
The
> >> schematics and the circuit board design hint to the direction
that
> > IC707
> >> "feeds" IC704.
> >>
> >> The IC707 is a 4558, I assume that it is similar in the Polysix.
> >>
> >> Did anybody of you experience a similar problem? What about
> > replacing
> >> the 4558, did this help?
> >>
> >> Furthermore, some of the 4558s carry a date stamp of 1997 which
> > means
> >> they must have been replaced by an earlier owner.
> >>
> >> Unfortunately there is no shop selling electronic parts in reach
so
> > I
> >> can't just go for it and try replacing it. Mail order is an
option
> > but
> >> not for a few ICs...
> >>
> >> Thank you for commenting.
> >>
> >> Best,
> >>
> >> Niels
> >>
> >
> >
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > Yahoo! Groups Links
> >
> >
> >
> >
>