Discussion about the Korg PolySix synthesizer

I finally got my klm-367 working again (it had been on the fritz ) and 
got the polysix all working and programmed  but noticed that when i set 
the three way modulation selector switch down to VCA  i suddenly heard 
a noticeable amount of white noise behind the desired sound. this white 
noise is also affected by the mod-rate knob so that when the knob set 
to any rate the noise pulses in the background when NO notes are played 
and is a bit annoying. the other 2 positions of that switch  vco and 
vcf  are quiet...no problems there ,  just the vca setting. any ideas? 
if i can clean that up its running at 100% after a year in the shop. ( 
perhaps  then time for that 'double your memory'  mod?)

Hi,

Just a couple of things of note. I had a problem with noise with the 
MG in VCA mode. This was a sort of thumping sound and was caused by 
processor port lines P24 being disconnected and the 4042 not clocking 
through data in a sychronised manner. However, if the sound is real 
white noise and a hisssssss then might I suggest you look at the 
signal path running through KLM-368 in and around IC20/21. In order 
to spot the parasitic oscillation you'll do well to find and use and 
oscilloscope for this problem.

Good luck and festive fun to you.

Cheers,
Andy


--- In PolySix@yahoogroups.com, "wasteking1" <wasteking1@...> wrote:
>
> I finally got my klm-367 working again (it had been on the fritz ) 
and 
> got the polysix all working and programmed  but noticed that when i 
set 
> the three way modulation selector switch down to VCA  i suddenly 
heard 
> a noticeable amount of white noise behind the desired sound. this 
white 
> noise is also affected by the mod-rate knob so that when the knob 
set 
> to any rate the noise pulses in the background when NO notes are 
played 
> and is a bit annoying. the other 2 positions of that switch  vco 
and 
> vcf  are quiet...no problems there ,  just the vca setting. any 
ideas? 
> if i can clean that up its running at 100% after a year in the 
shop. ( 
> perhaps  then time for that 'double your memory'  mod?)
>