Discussion about the Korg PolySix synthesizer

Just checking in see if any further steps to trouble shoot this one..

- Daniel

--- In PolySix@yahoogroups.com, "Daniel A" <apophis93@...> wrote:
>
> Andy,
> 
> Let me correct something about pin 2 of T3. In relooking at these values this morning VR5 does change the voltage the top end is what I stated with a slight saw wave pattern at 0.35v the counter clock wise position will bring the voltage down to -9v. This is with the MG Freq set to 10. When Freq is set to 0 VR5 does not appear to have that much of an effect on voltage.
> 
> - Daniel
> 
> --- In PolySix@yahoogroups.com, "Daniel A" <apophis93@> wrote:
> >
> > Andy,
> > 
> > 
> > > Just wanted to clarify something. Looking at the transistor, sloped face
> > > towards you, is the reverse of what you see in the schematic. So the
> > > left-hand base physically is the right hand one on the diagram. I have some
> > > further readings for you as the emitter voltages don¹t look quite right. 
> > 
> > Correct.
> > 
> >  
> > > Pin 1: fixed 5.0v
> > 
> > Good
> > 
> > > Pin 2: -13.95v to ­3.5v (0 ­10 on MG freq)
> > 
> > Well it goes down to -13.95v but only is hitting 0.35 to 0.4v on the top end.
> > 
> > > Pin 3: 5.4v to 5.6v  (0 ­10 on MG freq). This centre pin is the emitter and
> > > this should also alter in voltage as you adjust VR5
> > 
> > Yes when you rotate MG Freq but no change when adjusting VR5.
> > 
> > > Pin 4: Fixed 5.0v
> > 
> > Good.
> > 
> > > Pin 5: 4.7 to 4.9 as above.
> > 
> > Good.
> > 
> > 
> > > 
> > > BTW Have you noticed the transistor is symmetrical? You can solder it in
> > > either way!
> > > So, as you can see. Pin 16, IC21 should fluctuate quite a bit depending on
> > > the MG freq. setting. Sorry I am not getting to the bottom of this for you.
> > 
> > When adjusting the MG Freq Pin16 of IC 21 is only shifting perhaps a half of a volt on this board.
> > 
> > > This remote diagnostic business is pretty difficult at the best of times.
> > 
> > 
> > I really appreciate the support in getting this one running.
> > 
> > - Daniel
> >
>