(1) putting in dedicated power lines with armoured cable was a quantum leap upgrade in performance when compared to the effects of the power cable itself. Power cables by themselves without doing this may be an improvement but only a comparative small one at best. Complete the cradle-to-grave power upgrade with an upgrade starting at the panel first.
(2) contemporaneous with the dedicated lines (a separate one for the amp and another separate line for the source) I also upgraded the wall plugs to --
(1) first, to Hospital grade plugs, --and then--
(2) further upgrade later to expensive audiophile grade wall plugs.
The latter are gold plated high grade pure copper with no nickel, brass or ? Components ( gold plated is oxidation resistant but pure copper is VERY soft .. So be careful and don't bend them cuz it's very easy to torque them and thus do so...)
The latter new plugs are a further incremental "last step " upgrade to the hospital grade wall plugs, but only on my "A" system would I say they are worth the added not insignificant cash outlay.
(3) Power conditioners -- a potential BIG limiting effect and crappy resolution limiting clouding veil.
Sure ... In some circumstances they may prove fruitful if you live in an area with wild power swings or crummy old wiring blah blah etc.
HOWEVER... a dealer twigged me in to the tip that many high-end gear with their robust power supllies do NOT need NOR WANT any intermediate PC insertion ... The latter can actually be just a messy added limiting filter that creates a step-down in resolution.
He personally demonstrated it to me in my own system in MY home .... Damned if he wasn't right to the step-down of a PC in MY system. The performance downgrade with the PC in was not subtle.
YOUR TAKEAWAY. : be careful... It's no "one size fits all " here either ...
Again ...a PC is VERY system dependent in the first place, and maybe even an entirely avoidable step-down in a high-end system with its inherent robust high-end power supplies.