Replacing generic RECEPTACLES

First, you're lucky to have all new wiring giving your panel clean connections. Mine is old, that's why I have a new subpanel.

The best position for the audio breakers is away from the high current appliances such as refrigerator, furnace,  A/C, hot tub. I think you should try to have some space between the audio circuits and these appliances. Since it's newly wired it should be easy to relocate a breaker or two. My electrician moved some breakers to install the subpanel.

Imagine your amp, preamp breaker sits next to the refrigerator or A/C. Those appliances are always running, sending noise down the line to their connections plus your audio breakers. In this case, you would either move the audio breaker or move the appliance breaker.

@elizabeth @lowrider57 ...Thank you guys ....... I will have my electrician see what he can do about moving the audio breakers or appliance breakers while he adds the new dedicated 20A line. So you are also suggesting the audio breakers be on the top of the leg and high current appliances below .....  

Thank you guys ....... I will have my electrician see what he can do about moving the audio breakers or appliance breakers while he adds the new dedicated 20A line. So you are also suggesting the audio breakers be on the top of the leg and high current appliances below .....  

This is exactly what I mean about people on this forum, who really do not know what they are talking about, giving out very questionable advice about "gimminks" and "tweaks" that can cost serious money and accomplish virtually nothing vis-a vis audio performance.

Gee dynaquest4, what part of: ""I do not know if moving the wires in the box would actually matter. Sorry I cannot advise you on that."" did you miss? maybe all of it? Smearing everyone since that is the easy way? Or because your theory is always right and everyones else actual experience is wrong?  Whatever, please get over it.

Well, @dynaquest4, perhaps you should question Jea our resident electrical expert.