Hello I read a thread on the unrelenting hum and I hope that someone could help.

I have a hum that I hear in every speaker. I had an electrician friend of mine come over twice and for the most part have eliminsted the hum except from two locations. The cable box, which does not surprise me and my projector. I have the Infocus 7205. I am now running the 7205 on an (outside dedicated room) 15 amp circuit and there is no hum. I would like to reconnect the 7205 to the outlet in my Home Theater Room but then I have the hum.

This is my situation. Prior to having the electrician come over I dissconnected everything and re connected every piece of equipment. I still had the hum. However I ran a heavy duty extension cord to an 15 amp outlet outside my dedicated room and the hum was gone.
I have four dedicated 20 amps in my room.
Thirteen 20 amp circuits on my 100 amp service. My friend said that was not an issue. However most of the 20 amp circuits are on the one side of the box.
I was thinking of two things.
One was to move at least two of the 20 amp circuits to the other side of the box or make two 20 amp circuits 15 amps. I had read somewhere that there should be a balance in the circuit breaker box. If not you could have problems.
I believe that I could interchange the breakers without changeing the wire since it is 12 gauge wire for the 20 amp and I would be reducing the amperage not increasing it.

I do not know what else to do. I have a ground rod. I have a ground bar attached to my line conditioners and in turn hooked to a cold water pipe.
The electrician checked all of the circuits for proper grounding.

I would appreciate any ideas you would have and also your opinion on mine.

Thank you and....Happy New Year!!

Frank