The reason to do any electrical stuff is to take care of obvious problems and to increase isolation, the "quiet" that really makes high end audio. If the other aspects of audio reproduction are done properly (including the room), most of any remaining improvements seem to come from dropping the background soundfloor. This is the masking against which all else operates against.
Since I believe in basics, I would start by replacing your wall duplex receptacle with an isolated ground hospital grade unit. The PS unit incorporates all the possible improvements the manufacturer (Hubbell) lists (with a hefty profit for PS). I'm using a 20A cryoed isolated ground hospital grade Hubbell unit. When installing your new plug (after turning off the circuit at the breaker box!), chemically clean the wires, attach in proper polarity and tightly for a good mechanical connection (airtight). Now you can get all that's at the wall to your components. I switched my lights with rheostats to a different circuit to isolate their possible rf. Also plugged the CD players into a separate filter to isolate their possible RF. Chemically clean all plugs with CAIG's DeOxit or equivalent. Just use a product for 1) nonprecious metal surfaces, and 2) one that cleans as well as conditioning the contact surfaces.
As I understand it, the fundimental electrical problems to be overcome are 1) sufficient and appropriate conductor, 2) isolation from extraneous electronic signal (micro-arcing and rf), and 3) airtight, conditioned mechanical connections. Proprietary wire structures, aesthetics, and snake oil aside, these three are what you are hearing. BTW, I do not have a video aspect to my #1 audio sustem, largely because of all the RF problems that would introduce, but secondarily because I am not in a position to power that range of additional hardware at any one place in my house.
For my components with removable cords, I found some solid, well reviewed cords on Audiogon for about $50 each. These have soldered rather than simply pressed electrical connections. I'm also using a basic JR designed DIY filter for my front end components. All the mechanical connections, power cords as well as interconnects and cables, get revisited every couple years for chemical cleaning.
All that said, I think I realized my biggest improvement in isolation through mechanical isolation of the components and speakers. I"m using a Sanus isolating rack filled with graphited steel shot and spike coupled to the concrete slab beneath my flooring (the rack itself with shot and marble top slap weighs over 180#). The former Frieds (as well as the present B&W 800s
) are spike mounted as well. This was the improvement (with the Frieds) that caused SWMBO to come running in and accuse me of getting all new hardware behind her back. That's a pretty impressive testimonial to the efficacy of the tweak.
And all that said, this type of tweak in cummulative; you keep adding to your improvement and isolating your problems. Just remember the basics, and IMHO, mechanical isolation bought me more improvements than electrical isolation did.