In my case I had a great opportunity to install a dedicated circuit while my system was running off another circuit -- the breaker panel was located in my listening room and simply by switching the system from the south to the north wall, it was super easy for the electrician to drop a 5 foot piece of wire straight down from the panel and install a 20 A quad outlet. I used a pair of jena labs 20 a cryoed outlets, then moved the system and was floored by how much of an improvement the dedicated circuit made. Caveats -- I live in a condo and at least 2/3 of the people in that building worked at home, meaning all kinds of computers and other things online all day and night, plus 2 units down from the boiler room with all it's pumps controls, fire panel, etc., and I used a piece of the JPS labs house wiring wire, so not sure how much of all that stuff figures into the end result as my system sounded decent before this change, but easily far better, and at all times of day afterwards, and with no additional power filtering, just an outlet strip and the dedicated outlets on the wall.
Now I'm using an equitech balanced power box and it's significantly better than the dedicated outlet was (assuming all devices are plugged into the box), and that's in this new house where there is no possibility of a dedicated circuit.
So, in my case, even though I didn't think I had any particular power problem, the dedicated circuit made a very significant improvement to the sound of my system.
HTH,
Jim
Jim Rebman -- recovering audiophile
Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).
s.e.x. 2.1 under construction. Want list: Stereomour II
All ICs homemade (speaker and power next)