Discussion about the Korg PolySix synthesizer

Hi Jed,

first I'd like to thank you for what you did for the P6 itself and of course its users! Even if my P6 doesn't work yet I remain positive :)
I also appreciate you fast answer! thanks!

I fixed the R52 and R98 issues. I was hesitating by doing the last one ( lift the resistance 9 and cut the trace) I did it : unsoldering one leg of the R9 cut the trace and put a jumper between the CN 06 pin 02 and the unsoldered leg of the R09.

No more sound at all !Well, I can hear on the background the modulation if i put the gain  very high of the audio amp. The knobs on the MG panel remain unusable

Before to did the fix, I was able to hear the notes played through the modulation generator which went in and out very slowly in any MG mod ( vca vcf )with a very normal volume. I'm sure that the sound is modulate because I can follow the MG led with the fade of the sound

I don't have done the VR adjustments yet because I don't have any access to an oscilloscope. But I'm not sure it will change a lot. My first target is to have the sound back without the modulation on it  .

Should I put the R09 back and remove the jumper? and try something else? Or should I try to do the Don B. fix on the 368 board?

Could the problem on my P6 come from another part?

Cheers!

Vincent   



--- In PolySix@yahoogroups.com, Jed Jorgensen <jed.jorgensen@...> wrote:
>
> Hi Vincent,
> 
> Did you fix the two PCB errors noted here (#1 & #3):
> https://sites.google.com/site/jedjorgensen/klm367a/images/pcb-bugs-errors
> 
> <https://sites.google.com/site/jedjorgensen/klm367a/images/pcb-bugs-errors>Also,
> did you calibrate the board following the build as per the service manual?
> 
> Jed
> 
> On Thu, May 13, 2010 at 3:07 PM, kluberrrrr <KLBR@...> wrote:
> 
> >
> >
> > Hi everybody,
> >
> > I'm quite desperate here, so I hope someone could help me a bit especially
> > because I'm not very good in English and I'm not an electronic guy!
> > A couple of years ago I found a polysix which had the famous leak battery
> > problem, so impossible to play on it.
> >
> > I tried to repair the KLM 367 but with no success.
> > Then i discovered the Jed's project
> >
> > Today I've just finished to solder all the parts on the KLM-367A clone
> > board.
> > I put the board back on my P6. Then I turned it on.
> >
> > First, the programmer panel seems to work fine, Led button repond when I
> > push them
> >
> > BUT there is no sound at all. Just some attack sound, some 'blops'.
> >
> > When I hold a key down, I can hear the note coming very slowly and fade
> > out. Just like the LEd of the MG panel fading In and Out very slowly.
> >
> > The Mg frequency, delay and level's knobs don't affect the modulation. Even
> > if the modulation level is at 0, the sound is fully modulated
> >
> > So I guess it's the MG section which seems to not work properly. It looks
> > like it is stuck on a very slow frequency and there is no way to cut the
> > modulation.
> >
> >
> > Also cutoff, resonance, eg int, keyboard track knobs don't seem to change
> > the sound.
> >
> > When I built the new Jed's PCB, I used from the old board the mask rom IC,
> > the TC5514APL-3 IC, the two LM13600 ICs and the 2SA798
> >
> > What do you think? Is it possible that one of the Ic is dead? Or does it
> > look like the problem is deeper?
> >
> > Please excuse my poor english !
> >
> > Cheers!
> >
> > Vincent
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>