Dedicated Line Noise Filter?

@lowrider57 One must look on eBay but you can find used ones at a reasonable price. That's what I did.
What State do you reside in?

No need to filter at the breaker box!

Buy a Chang LightSpeed Line Filter which you can plug all your audio equipment into.

Has Digital and Analog AC sockets.

Does not limit current inflow!

Works great IMO!

http://www.changlightspeed.com

You may be right, gdnrbob. I think the surge/ noise reduction unit was about $700, but I have found some online for less. I get the feeling the electrician will only install the brands that his company uses. He had a binder showing the different units available.
However, he was fine with me providing the Romex and Hubbells for the installation.

@lak , I'm in Philly, PA (a row home). How did you determine the rating of the transformer (5 KVA) for your needs?

@don_c55 , thanks, but I've got a limited budget and I've already invested in Blue Circle and Brickwall PC's plus some Blue Circle line filters.

If you feel sure this is a mains noise level issue and not some kind of equipment thing going on, then I would recommend Alan Maher Designs, despite that most audiophiles have little or no experience with them. I’ve been dealing with Alan since 2010 with full confidence in what he says and what he does. I know for a fact he can reduce mains noise levels because this is essentially the kind of problem he handles all day every day.

I know the normal products he would recommend for ordinary standalone homes, but for a row house, you will need to contact Alan directly through his company site on facebook (Alan P Maher, or alanmaherdesigns.net and fb message him, he will respond to your q’s within a day). Don’t worry, he has grounding and noise-reduction expertise with electrical systems worldwide so a row house will not offer him any real challenge. For the said normal house, a good solution with his stuff would be around $300-$350, with always the option to expand from there if you liked what those changes did to the sound quality (the improvements of which being the real attraction to Alan’s approach...reducing electrical noise = much improved sound in all departments, not simply just a reduction in perceived background hiss or audible noise, of course).

Lots easier and just as effective in most cases as dealing with balanced transformers. Installation of the AMD stuff IME is a breeze although it usually takes about 30 days or so to fully come on song, but I’ve found everything I’ve ordered from him to work as advertised to say the least.

Some, or possibly even all, of the products he will recommend to you can be applied directly to the breaker box.

Thanks @ivan_nosnibor , I'll look him up.
I don't believe it's component related, but tomorrow I plan on removing all power conditioning and surge protectors to eliminate extra circuits and cables.

I swapped the SS with a tube amp tonight and the same amount of noise was audible.