[nlitworld]

Another thing I totally forgot that really helped in my noise situation is rca caps to short the unused inputs. I realize it sounds like a stupid little tweak, but it really did help. Plus an Amazon deal you can return the next day if it doesn't help, so no risk at all.
Amazon link here

[andyr]

I installed a dedicated line for my audio rig when I renovated my apartment, purchased fancy Furutech outlets and covers and still have a bit of 60 cycle hum from woofer and buzz from tweeter.  It is inaudible until you put your ear within a foot of the speaker. 

Then you won't hear this noise from your listening position.  Which is all that matters!