I've just introduced another dedicated line to my system for the digital gear.
That's three dedicated lines, and no hum issues.
If anything, less noise.
If someone claims that adding dedicated lines created hum or noise, then perhaps it's a bad electrical connection at the panel,the lines are not all on the same side or phase of the panel or that some noise inducing appliance such as the funace AC or refrigerator share close proximity with one or all of the dedicated lines at the panel.
Have an electrician come over and see if he can balance out the amount of draw each half of the panel has.
In my case, the AC is on the other side of my panel, and so are some other things,even so, my sound is better when I turn off the AC breakers in the fall.
Dedicated lines in conjunction with upgraded power cords and conditioning( I use Shunyata, but have no affiliation, so don't call me a shill)have made quite the improvement in my system, and when you can make improvements to what you've already invested in makes more sense than to jump on the merry go round looking for the perfect sound.
The perfect sound might already be in your system but you just haven't heard it yet.
Give your gear good power and you'll be quite pleasantly surprised.
