Discussion about the Korg PolySix synthesizer

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
>