a soft 60Hz hum problem

[mweston]

Power conditions have forced me to add electrical service to the home It was so bad that the McIntosh system would shut itself down. The electrician did a best effort to install circuits that were isolated from the outside box and 18 inches away from the other steel conduit. Unfortunately I have a very soft 60 HZ hum coming from the front 3 speakers. Rewiring the piggy back breakers did not improve things and was put back the way it was done originally. It was wired with 10 gauge Romex for use with a Purepower+ 3000 unit which has yet to ordered. A second 30 amp service was installed incase I need another Purepower + 3000 unit. To 20 amp service circuits were installed to provide power for the time being. I do not get hum from McIntosh MC7300 because it is wired for 2 conductor power cord. I unplugged the MC602 amp and connected it to the house's original 2 conductor wire outlet that has a Synergistic Tesla outlet. NO HUM!!! This leads me to believe that the problem is systemic since I have never had this problem and comes from the new power outlets. I have a fellow McIntosh friend and electronics tech who wired from his box 4 gauge telephone wire to his outlets. He measured some voltage on the neutral-leakage. He decided to live with it. I do not believe either one of us has wired wrong circuits. My electrician came back and wired a grounding rod to the outside box. No change. I am using Synergistic power cable with electric shielding. The amplifiers are not stacked on top each other- separated by ventilation grills. Any thoughts, suggestions, or solutions on your part?

[Chad.Wagner]

Try turning off all breakers except the one you are using to see if some other electronics in the home are the problem. If the problem goes away, turn on each breaker until the problem comes back. If you can find the circuit introducing the noise you should be able to find the device or wiring that is creating the noise.

If the problem continues with only one circuit turned on, unplug all other devices on that circuit leaving only your amp and preamp. Then start adding the devices back. It is not good enough to turn the devices off, you need to unplug them.

The Purepower should be able to hide the problem, but it is worth the effort to get it fixed.

Let us know what you find.

Good Luck!