New Dedicated Line - Almost No improvement

@laynes 

Just to review; you have one dedicated 20A line to the service panel. The audio system used the last available breaker (if it's one line, the electrician would have used a standard breaker). Look at the panel, are there any breakers for high-current appliances close to the audio breaker? And are there any on the same Leg (phase) as your audio? Phase will usually be indicated as A or B. Breakers 1,3,5 would be phase A. Breakers 2,4,6 are phase B (in most situations).

Heavy-duty appliances such as A/C, fridge, washer will introduce noise back onto the mains.

A completely different way......and a much better way.....sonically....is to get off the frickin grid........Check this out:

http://tweakaudio.com/EVS-2/Inverter_Power.html

I will have more info in a day or so.....but this is mindblowing........The same great sound day and night......way better sound than you ever imagined......and you can buy a 2200 watt inverter for a little over $300.....then some batteries and charger and you will be in heaven.....of course, there is more......as described.

Any serious audio geek owns a home with a stream you can dam up for your own hydro power...a small nuclear plant also works but be wary of sensitive neighbors.

Juice is juice.  As long as you get the noise off the line.

Seems to me that with rechargeable batteries abundant now from puny right up to car size, the way to go is to use battery power.  Choose battery(ies) suitably rated to power your components, charge them in system downtime and disconnect charging while listening.  A car-size battery easily has the capacity and punch to run my Krell KRs200s.  Eureka.  All noise gone, no need for dedicated power lines, fancy power conditioners $15,000 power cords.

Why not?

@laynes 

Have the grounding in your house checked.