2. amps-preamps
  3. 1347156354

Amp hums in standby mode when TV is on

Hi, my Sherbourn 5/1500A power amp starts humming whenever the TV in the same room is operating. This occurs even when the amp is in its standby state, and also happens when using the amp(although you can't typically hear the humming at that point because of the sound from the speakers). What's more, as the image on the TV varies in brightness, the intensity of the humming/buzzing also varies. If the TV is off, the amp is dead quiet. I am assuming this is some kind of ground loop problem.

Should I try to plug the amp in with a "cheater plug"? There is a sticker on the back of the amp that indicates that the amp must be used with a grounded power cord.
mtrot

Showing 1 response by davehrab

davehrab's avatar
davehrab
380 posts
 
IMO ... the DC offset created by the half wave bridge rectifiers in all the switching power supplies of our equipment is a silent killer

The Humming that is heard at the transformer is only the Symptom ... the real Disease is the loss of head room and reduced dynamics when the transformer’s efficiency is compromised by the DC off set saturating and rattling the transformer when that extra pulse is drawn

When a system is infected with RF you will hear the RF irritating you and effecting the high frequencies ... if your system has issues with EM (the magnetic side) ... you will hear a humming

But enough DC offset and the transformer’s efficiency is reduced and things just don’t sound as dynamic or authoritative ...

I feel you can clearly hear the effects RF and EM .. but a reduction in efficiency and head room is hard to realize until it has been corrected

I use two PS Audio Humbuster III’s in my system and was shocked at how much more powerful and authoritative the system sounded ... the character and tone of the system never changed ... it just sounded more powerful after unplugging everything from my EP15 Exact Power and plugging everything into the two Busters
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