Doepfer

Hi

we had similar problems last week within a large live setup. Around 15 
musicians with computers, lots of synths and softsynth, all mixed to 
submixers, which are led to a main mix. The lenght of the power and 
audio cables are 6 meters for the most musicians at least.

Though this sounds like a bunch of humm traps the most participians do 
not have real problems, but two guys:
Finally we could track down that these two are using USB-Audiointerfaces 
where the interfaces are powered by the USB port, not by an external 
supply. This means that you have the dirty ground of the digital domain 
as audioground.

Our solution now was simply to forbid this type of audiointerfaces.

Florian

stuadh wrote:

> Hi,
> 
>   I would like to appeal to anyone with experience in eradicating a
> probable ground loop.  I've just done a bit of upgrading in my studio,
> and I've developed a nasty buzzing in my system.  I've narrowed it
> down to the interplay between Logic 7 and my analogue synth.  Of note
> is that I have not changed anything inside the synth since before the
> upgrade and that the problem exists even when the synth is turned off
> but not when it is unplugged from the wall.  In fact, I've just been
> jiggling about with the plug and the buzz come back as soon as the
> earth pin of the plug makes contact.
> 
>   The problem also only exists when Logic is running but not when i
> run things like iTunes etc.  It can also be controlled by the mixer;
> turning down the channel volume or EQing it out work.  I've also gone
> around turning off and unplugging everything except the computer,
> synth and mixer, but the buzz remains.
> 
> Can anyone help?
> 
> Yours Aye
> 
> Stuadh
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
> 

-- 
Florian Anwander                  |ConSol
Tel.   +49(89)45841-133           |Consulting&Solutions Software GmbH
Fax    +49(89)45841-111           |Franziskanerstr. 38, D-81669 München
email: florian.anwander@consol.de |http://www.consol.de