The QO series uses a solid copper buss bar. However it is electroplated to reduce oxidation and looks silver in color.
Although I think that splitting the electricity immediately after the meter is better, I had room in my original outdoor 200A breaker box to put in a 100A breaker for the subpanel. I then ran 2 gauge copper cable from the main panel to the new indoor subpanel about fifty feet away in the basement. (Copper prices have shot through the roof over the past year, so this was actually the largest expense of the project.)
I ran four new dedicated 20A circuits to the AV area using 10 gauge copper wire ending with PS Audio PowerPorts. I chose Square D QO AFI (arc fault interupter) circuit breakers. With only four breakers, I still have plenty of room in the subpanel for future use if I need it.
The job wasn't pure audio reference quality, but the improvements in simply having the dedicated sub-panel were worth it.
I looked at installing some serious commercial quality whole house surge and spike protection at the subpanel box, but there were so many other ways for surges and/or spikes to enter the system (antenna/cable/phone/satellite/other AC circuit connections), it made more sense to do it up front at the main box. Although that's something I'd still like to do, I haven't done it yet.
Let me know if I can answer any more questions.
Cheers,
Tom
