Discussion about the Korg PolySix synthesizer

Hi all,

we all know the Polysix is pretty noisy (some units more than others), even more so with the Kiwisix board. While my line output seems acceptable now, the headphones output is still very noisy. I've done all the calibrations in the KLM-368 and soldered ground wires from the analog outputs to join the digital grounding wires. It has improved things but I just can't seem to match the lower noise of the main output. Does anyone have more suggestions? Thanks in advance.

Sorry, but the after dynamic effects low pass is intended as a 
noisereduction for the effects section. It may happen that its cutoff is 
set too low due to the deviation of the caps values. In this case you 
may reduce C67 and C72 to 360p or 220p. But I would never bypass them, 
because this will increase the noise significantly when the effects 
section is enganged and no notes are played.

Am 22.12.2016 um 12:00 schrieb ninonine@xs4all.nl [PolySix]:
> Thanks for the cap reduce info, will look into that. One could also 
> bypass the effects entirely or put a LM13700 instead all are options 
> subject to taste. I wonder btw did doepfer fix the BBD clock generator 
> noise in the (tapped) bbd A-100 modules? This might also be a good 
> Question for the Doepfer group that we also post in :)
That "noise" is intended. See http://www.doepfer.de/A1882.htm

"A voltage composed of the manual delay control, CV1 and CV2 is 
available at the CV out socket, e.g. to control an external clock 
suppression filter as the A-188-2 is not equipped with such a filter 
(same as for the A-188-1 <http://www.doepfer.de/A1881.htm>)."

and additionally from the same page:

_"Important note (especially for A-188-1 users)_: /The A-188-1 uses 
single BBD circuits, which can be adjusted to minimize the clock noise 
as the outputs of the used BBD circuits are symmetrical (for details 
please refer to //A1881_adjustment.pdf 
<http://www.doepfer.de/service/A1881_adjustment.pdf>, trimming 
potentiometer P10). By way of contrast the BBD circuit used in the 
A-188-2 (MN3011) has six asymmetrical outputs that cannot be adjusted to 
minimize the clock noise. In addition the clock noise of the six outputs 
adds up. From there the clock noise of the A-188-2 is more intense than 
of the A-188-1. This is caused by the properties of the MN3011 but not a 
mistake of the module ! If you feel that the clock noise is too much you 
have the right to return the _unused_ module within 14 days (i.e. the 
module has no scratches or prints, e.g. from srewing into the frame)."/