Am I hearing things?


I just an extra  new dedicated line run beside the other one. with 10 gauge wire, 30 amp breaker and a 20 amp rated outlet. I don't think it sounds as good!!! What the hey. A little shrill in both vinyl and CD. I'm comparing from what it sounded like last night. Does electricians wire, breaker and outlet have to burn in? Am I alone in this. I'm have a whole system AC but in and the temp got up to 80. Maybe that is why. Also I'm listening at 11 am EST. So the power grid may have an affect. Did I just answer my own question or have other people experienced this. The original dedicated line was put in in 03 with 12 gauge wire, 20 amp breaker and a 15 amp outlet. Are these 2 lines picking up interferrence? 
128x128blueranger
There are others here with real technical expertise in electrical systems, I can only respond anecdotally. When I moved to a new/old house, I installed an entire subsystem for the electrical, and even before the big isolation transformer arrived and was installed, the wiring was connected via a "J’ box (presumably a "junction" box). The system was largely the same, but the room was different. And, yes, the system sounded a little bright at first, but the power here (I’m now in Austin, very close to downtown, and not far from a lot of commercial stuff, though in a strictly residential neighborhood) was much cleaner, without any treatment, conditioning, etc. than what I was getting in NY (not in Manhattan but in a small village north of Manhattan).
Part of it may be the result of newer infrastructure, or who i'm sharing a transformer with- i know I'm not on the same transformer as the apartment buildings nearby. 
So, the power coming in is certainly going to have an effect, as will the amount of demand on the ’grid.’ It’s been upwards of 110F here and I can still play the system, but I know it would probably sound better, despite the isolation transformer, if the incoming power wasn’t in such great demand right now due to heat.
As to ’running next to,’ how close? I think there are best practices in terms of spacing the lines. I’m not going to address the use of a 30 amp breaker since you may have some need for that.

blueranger:

Why did you need to go to 30amps? Just fitted my system with a 20amp circuit for just the class A monoblocks and that's plenty of power. Are you using any kind conditioner or isolation transformer? The latter will solve those grid problems you refer to.

Post removed 
I put two 20a dedicated lines in the new house when we moved in last year. Took them a couple weeks to lose the shrillness and settle.