First make sure there are no motors on that circuit. If not, then use a receptacle tester (the one that plugs in with three lights) and see if it is properly wired. Next step is to check for an unbalanced neutral at that receptacle. Measure both hot and neutral with respect to the ground. Anything more than a few volts on neutral to ground is not normal. Also check the hot to ground voltage at all other receptacles on that circuit. Any difference is the results of loose wiring, which can cause arcing. Any of the above will make transformers sing.
Can moving wire location at circuit breaker reduce hum?
The power line going into my music room will oftentimes make the amps’ transformers hum. I’ve tried many things but have had no luck. If I take any component that’s humming into a different room run on a different circuit breaker, the hum disappears.
Would swapping out the wires that go into the two separate rooms at the breaker make any difference? Or is it more likely that one of the outlets on the circuit that goes into my music room is somehow miswired and is causing the hum? I can unplug everything from the circuit except for my amp and it still hums.
Any suggestions on what I might be able to do short of hiring someone to run a dedicated line?
Thanks,
Mamoru
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- 52 posts total
When I was building my room, I was advised that "the 2 dedicated 20 amp lines MUST be on the same phase leg. Otherwise I could get a ground loop". Is the hum present when the component is connected to amp with RCA/XLR, or just the component into the electric outlet? Because if you just connect the component to the electric outlet and no other cables are connected to that, then you can rule out the ground loop. |
@milpai That's correct but I think you missed that this is mechanical, not electrical hum. Mechanical hum comes from DC on the line, not from ground loops. DC is when the AC voltage is shifted up or down by a DC voltage. So the AC may be 120V, but it's shifted so it's 0 crossing is no longer 0. |
Fortunately, the first test, to identify if this is caused by another electrical component is fairly simple. Turn everything else off in the house. 😀 Flip off every breaker and make sure nothing is left on your circuit but your amps. If the problem is gone, you know it's something else, and that's my bet, but yeah, it could be a bad neutral. |
- 52 posts total