Re: [AH] Doepfer Opinions (PSU CROSSTALK)

From Cynthia Webster
Sent Fri, Feb 8th 2008, 20:37

Hi Guys!

I doubt it would the Zeroscillator creating noise on your Doepfer power 
supply rails because the ZO has one of the
most insanely sophisticated power filtering sections ever offered on any 
module.  It offers serious multi-wind ferrite coils and chokes
to quiet the rails from high frequency noise and has beefy regulator 
electrolytic caps  and ceramic caps to iron out any clicks or
fluctuations on the rails, (such as the sudden drain of a bunch of 
Envelopes firing elsewhere in a system on the same power rails,
in such a case the ZOs wouldn't even notice this.  Most other VCOs are 
not so well regulated and isolated in their own little (quiet)
world.  ZOs also have short-circuit protection, use special 
high-precision voltage reference chips (and thus doesn't derive Tuning 
from the plus and minus power rails)
the LEDs do not appear on the power rails at all.  We set out from the 
beginning to create a new very high standard in modules with the ZO.   
So far, so good.

Please try removing different combinations of these modules sometime and 
see what you find.

I imagine that you must have a wonderful time patching the 15's and ZOs 
back and forth, what fun!


Bakis Sirros wrote:
> hello Peter and Florian and list,
> ok, my experience (after using a huge doepfer modular with 18 G6 
> cases, for many years):
> i have not heard any crosstalk on doepfer modules, so far.
> the only crosstalk i have heard from modules mounted to my doepfer 
> racks, are from a row that has two plan B model 15 vco's.
> please, do not get me wrong, i love the module 15's , but they are the 
> only modules to which i noticed slight unwanted modulation (that's 
> crosstalk, right?) from other modules (i think the modulation came 
> from the other model 15, or the Cyndustries ZO, that is in the same 
> row... or from another module that used to be next to the model 15's 
> in the past)
> anyway, the problem is very small and not important for me, and i use 
> the M15 vco's normally! btw, maybe there is crosstalk to the ZO too in 
> this same raw, i am not sure...
> (btw, all these modules are mounted in a G6 with a PSU2 supply, but i 
> do not think that this matters at all)
> just my experience, but, no disrespect at all: i DO like doepfer and 
> plan B and Cyndustries modules!
> best regards,      :-)
> Bakis.
> Bakis Sirros
> Parallel Worlds / Interconnected / Memory Geist
> doepfer_a100 group owner
> Athens - Greece
> ----- Original Message ----- From: "Florian Anwander" 
> <>
> To: "analogue list" <>
> Sent: Friday, February 08, 2008 4:55 PM
> Subject: Re: [AH] Doepfer Opinions (PSU CROSSTALK)
>> 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