I just rewired the power to my system also, but did it a little differently - I put in a 240V circuit. I added a new 200A sub-panel next to the main service panel, used a 15A 2-pole breaker, and then ran four 6awg wires (2 hots, 1 neutral & 1 ground) through 1" conduit to a 240V outlet at my audio equipment. There I used a Richard Gray SubStation to drop the voltage to 120V.
At the the new sub-panel I put new ground rods into the earth and connected them to an isolated ground bar in the sub-panel. This is a ground bar that stands off from the sub-panel on plastic insulators - it had to be purchased separately and installed. The ground wire from the outlet connects to this. Code here does not connect the neutral wire in a 240V circuit, so I ran the wire but did not connect it. If any other circuits go into the sub-panel in the future I will connect them to the existing ground - the new ground is strictly for the sound system.
This set-up has proved to be very quiet for me.
At the the new sub-panel I put new ground rods into the earth and connected them to an isolated ground bar in the sub-panel. This is a ground bar that stands off from the sub-panel on plastic insulators - it had to be purchased separately and installed. The ground wire from the outlet connects to this. Code here does not connect the neutral wire in a 240V circuit, so I ran the wire but did not connect it. If any other circuits go into the sub-panel in the future I will connect them to the existing ground - the new ground is strictly for the sound system.
This set-up has proved to be very quiet for me.