Can moving wire location at circuit breaker reduce hum?

Hi

Looks like you have a pesky one. The way you described it is a little confusing though. Does the hum happen constantly or is it “oftentimes”?  Is the amp the only component humming or are there more?  You talked about “any component that’s humming”, what else is humming?  The fact that moving the amp to another room stops the problem tells you it’s not the amp. Have you tried different outlets in the original room?  To find out if the wiring is at fault, you can try a simple, inexpensive wire tester such as this one: Klein tool RT110 receptacle tester. Moving the wire should be your last result. Good luck. 

So, we are talking about a mechanical hum that you can hear or feel at the amp itself, right? OK, that’s a sign of DC on the line.

If you move to another "leg" of the panel it may fix the problem but only if the source of the DC is on another circuit. See if you can locate the source which is often something like LED power supplies or some wall wart somewhere or old dimmer switches. If the problem is on the same circuit as your audio gear then no amount of moving a breaker around will fix it.

If you are sure the source is not on your circuit, then try moving to another leg. Panels alternate legs horizontally, so pick a new location that is off by odd row numbers. 1, 3, 5, 7, etc. If you move horizontally or an even number you will stay on the same leg.

Of course, they also make DC blockers specifically for this purpose.