[BC] Humming Preamps

[seaberg1@sbcglobal.net]

Do you have any neon signs around the building ? They generate electrical 
hash
and also the transformers generate audio hum.  Also it is good practice to 
have
all equipment grounds run separately to a common ground point. This is 
usually
located near the power company step-down transformer at the building 
entrance.

Old doorbell transformers have been known to develop leakage or arcing, same 
for
baby monitors, etc.   Great hash generators.

Have fun....and good luck.

Bob Seaberg -- W3MDM



----- Original Message ----- 
From: "RadioPower Webmaster" <webmaster at radiopower.org>
To: <broadcast at radiolists.net>
Sent: Saturday, April 07, 2007 12:33 AM
Subject: [BC] Humming Preamps


> 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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