2. tech-talk
  3. 1225969274

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
consttraveler
250 posts
 
Remember to turn off (at the breaker) the house power before you take the outlet cover off to inspect the ground and +,-.

I know it is semi insulting to write the above, but having grabbed 220 once myself (and 110 more than once), it is meant in the kindest way.

Best regards,

Dave
rodman99999
6,035 posts
 
Cford has it right. Be certain that the black wire(hot) is connected to the copper screw of the outlet, and the white wire(neutral) to the nickel screw. You might even check the breaker box connections, while turning off the power, as Dave suggested. You should only see black wires connected to the breakers, and whites to the neutral buss(could be reversed there instead of at the outlet).
honest1
586 posts
 
Rather than pulling apart outlet and breaker boxes, follow Zapper's advice and get a 3 light tester. It looks like a yellow 3 prong adapter, with 3 lights on the back. You plug it into the outlet, and it will tell you if anything is wired wrong.
jea48
4,323 posts
 
Receptacle-Circuit-Analyzer
rockvirgo OP
587 posts
 
Thanks all for your responses. Those three light socket checkers are great but haven't been able to snag one yet. Visually, both outlets are wired identically and the breaker box looked ok, except for some red wires inside. My last guess is one of the two outlets is set up near the window aircon so maybe it has a separate ground.
More to discover