I have been running monoblocks on one dedicated 20A line and pre and sources on a shared 15A. I have some hum which is improved greatly when I put everything on the one dedicated circuit, so I want to add another dedicated line so I can have 2 quiet, loop-free duplex outlets. I was worried about the 100 feet of ground loop I would be creating by running them back to main panel separately. I googled and the only relevant posts I found were here on AC, imagine that!!
From bubba966, back in 06:
http://www.audiocircle.com/index.php?topic=24535.msg217627#msg217627 He says make sure you use breakers on the same phase to avoid hum problems, and shows which breakers give you that. I already have an unused 20A breaker on the same phase in my panel! Big help, thanks Bubba.
I assume two dedicated lines in phase would be inherently hum free even at long lengths because they are close to identical in length and ga, with no breaks in the ground wire, so resistance would be about the same, thus preventing hum. Does this make sense?
I thought about bonding the two circuits' grounds at the outlets (in addition to the standard connection at the panel) to eliminate the difference in resistance from the runs to panel and back but I'm sure that's not code. Just seems naughty.
Thanks
Rich
