Re: [AH] Doepfer Opinions (PSU CROSSTALK)

From Florian Anwander
Sent Fri, Feb 8th 2008, 15:55

Hi Peter

> Um...with all respect, there most certainly is an issue with  crosstalk 
> with current Eurorack power busses. The ground connections  on the 
> bussboards are daisychained, which results in an open path for  noise 
> created by one module to be  transmitted down the line.  As a  result,
> VCOs and some filters placed in the same rack (powered by the  same PSU) 
> as LFOs, EGs, and modules which use PICs or Microp's and  others which 
> are notorious noise makers will cause the zero  transitions of these 
> listed modules to be heard at the outputs audio  modules which share the 
> same power.  So by noise I don't mean white  noise, but I so mean 
> clicks, hums and audible LFO oscillations in the  signal path. This 
> effect can be lessened by connecting the power to  any audio modules in 
> shared racks as close to the main power inputs  as possible.  This works 
> in some instances.
Either I am deaf or I am lucky, but I had never those problems. Neither
with diy bus boards nor with original Doepfer busboards (in total 7 busses).
And also I have to admit, that I use to have audio modules on the left
side of the rack and control modules on the right side, simply because I
like having the oversight - may be this avoids crosstalk influeces
(though not intended).

Florian