Loud Buzz/Humm in Both BeePre Channels

AudioDave · 4443

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Offline AudioDave

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on: July 12, 2023, 09:57:48 AM
I have the original BeePre 1 which has worked great for many years.  A couple of days ago I noticed a very audible buzz/humm in both channels as soon as the preamp is turned on.  The humm is not affected by the volume control or selector switch.  The humm is not readily noticeable when music is playing but is very noticeable when music is not playing.  In researching the Bottlehead Forum I noticed a post that mentioned that low mains voltage might cause this problem.  I am in Texas and I just measured the wall outlet where the BeePre is plugged in and it showed 114 VAC.  Do you think this might be the problem or do I need to start looking under the hood a little bit more?!  I put my Foreplay 3 into my system for now and it is dead quiet!
Thanks for any suggestions
Dave



Offline Paul Joppa

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Reply #1 on: July 12, 2023, 10:25:35 AM
The low line voltage is very likely the problem.


Paul Joppa


Offline AudioDave

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Reply #2 on: July 12, 2023, 11:25:21 AM
That was it Paul!!   I was able to get my hands on a variac,  set it to 120 VAC, powered up the BeePre and Dead Quiet!!   Guess I need to look into building a "Boost Box" as mentioned in a previous post.
Thanks for your help!
Dave