Re: [AH] Doepfer Opinions (PSU CROSSTALK)

From Plan B (Peter Grenader)
Sent Fri, Feb 8th 2008, 20:54

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The M15 is a receiver, not a generator of noise (unless you patch it  
out the outputs!).  Its got all of the noise immunity circuitry the  
ZO has, but bypass caps at both the comparator and expo.

There are many others who are receivers.  At the risk of being a name  
dropper, let me just leave it at that so I don't list others which I  
am personally aware of. Filters of various manufacturers.

The M15 nor the ZO are  the problem.  A noisy power system is the  

On Feb 8, 2008, at 11:04 AM, 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

Peter Grenader
p: 888 791-0010