[BC] Humming Preamps

[Chuck G.]

Shelby;

Before you can eliminate the noise you have to know where it's coming 
from.  Is it in the AC power system, or is it something else that's 
being picked up?
Are there transmitters of any sort in your vicinity?  See anything on 
the powerlines when you look with a scope, other than 60 hz AC?
Can you hear it in battery-powered devices such as a walkman?  If so, 
does it change or disappear when you turn off breakers to your studios 
one by one?
Do you have a good ground (not the power company ground) available?


Chuck G.


RadioPower Webmaster wrote:
> I'm still having issues with humming in all our mic, stereo, and phono 
> preamps. It's a buzzing sound that seems faster higher frequency than 
> 60 cycle hum. More like RF static. It happens in all 4 of our studio 
> booths on two floors. It's so bad we can't use our turntables. I got 
> an electrician to come out and he ran new ground wires for the 
> building service and switch panel and replaced old vibrating breakers. 
> It still hums. He suggests running 20 amp lines with isolated ground 
> to plug strips for each booth. Before I lay down another $800 does 
> this sound like it might fix our problem? Also do the high end $450 
> Furman or Monster power conditioners work any better than the $150 
> Furman PL-8 rack mount conditioners we have? I'm starting to fear 
> thousands spent in a wild goose chase. By the way a Verizon tech had 
> to install inline RF filters to cut the humming and noise from our 
> phone hybrids. I've never met a building this noisy.
>
> Thanks in advance.
>
> Shelby
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