The absolute "best" filter/conditioner for digital

Mrtennis I appreciate your power cord advice. It confirms what my experimentation has shown. My Grandfather was a Mariner, and my close cousin is Port Captain in one of the major eastern ports. Mariners say there's a place for everything and out everything in its place. This is probably a good rule for us--it's just to find the perfect place.
I'm laid up after shoulder surgery and will be doing experimentation with what I have when pain is reduced.
These forums have been a great value to me over the years and your input is appreciated :)

Thanks for the responses!

Thanks again. I particularly like Zd542"s Cable Company info-i will use it. Also,Brownsfan advice will be followed up.
I agree with dedicated lines- but particularly if you isolate them with something like an Equitech or other balanced power transformer or another type of 'isolation transformer'-they strip away and tremendous amount of noise and can be cheap, used or factory blems or transfomers only that you can box and connect yourself, or any electrician. Be sure to buy over your requirements for best advantage. Even if only digital line is isolated the results are amazing. Always looking for new ideas though,transformers are old school but the balanced are current.

Silence.

April 23,2018. Enjoyed the sound field and clarity of a solo piano from the best front row seat in a great venue yesterday. I’d like to update this thread as many new offerings have hopefully raised the bar. I understand a symmetrically balanced large isolation transformer is perhaps most efficient and best for “common mode” ac noise. I’m open to all new technologies as innovation is our never ending ally. I’m particularly interested in units/technologies addressing “differential mode” ac noise. Cheers! to silencing ubiquitous ac line line, both incoming and “within” our systems. Thanks for your contribution.