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House Wiring Defect?

Recently I introduced a new power amp connected to my preamp with XLR cables. The pre and power amps were plugged into different outlets in the same room which produced a pretty loud hum from both speakers with the preamp on or off and the power amp on. After the inital freak out and a check of all connections I realized one fix was to power the pre and power amps from the same outlet. This restored quiet operation using either outlet. The question is, does this indicate a house wiring defect or nothing to worry about?
rockvirgo

Showing 1 response by zapper

zapper
68 posts
 
It seems the 2 outlets were on different phases of you house electric, which induces a hum. With them on the same outlet/phase, hum is gone, makes sense.
You house is probably fine. You can use a 3-light tester to see if the wires are reversed on either outlet.
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