Thanks very much !
The tuning is bad on both VCO1 and VCO2 of that oscillator (although
it seems more extreme on VCO2).
I uploaded the schematics diagram for the VCO board to the files
section - what would be the caps to check on that one ?
Thanks again.
--- In
PolySix@yahoogroups.com, Johannes Hausensteiner <johau@g...>
wrote:
>
> Hi,
>
> I only have the schematics for the MK I; which I do not know whether
> it is similar to the MK II. Which VCO has the problem? Is it VCO-1
or
> VCO-2 or both? If it is both then hacve a look at the hold
capacitors
> after the VCO CV demux IC15 (a 4051) on KLM-301 board. These are
the
> caps C25 - C32.
>
> Good luck,
>
> Johannes
>
>
> gil_we wrote:
> > I've been recovering this one, found in the flea market. Overall
it
> > had about 8-9 different faults that I fixed, leaving two problems.
> >
> > The first is a bad SSM2056 chip which I need to find. The second
i
> > probably inherent in the discrete ciruit of the second oscillator.
> >
> > Upon powering it up, that particular oscillator will be out of
tune,
> > till it gets to its max. internal temperature where the tuning of
> > that VCO is geting more or less - stable.
> >
> > All other oscillators are immediately in tune, no matter what is
the
> > temperatue inside the machine.
> >
> > I, of course, tried to figure out what the bad component is by
> > blowing with a straw on each and each of the suspected compnents,
but
> > blowingon every component on the circuit of that oscialltor which
> > seems to be pitch related, seems to effect the pitch.
> >
> > I also tried to switch transistors between the bad oscillator and
> > another (working one) but the problem persisted.
> >
> > Does anyone have any other idea / direction ?
> >
> > Thanks
> >
> >
> >
> >
> >
> >
> > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
>