I use a ’extension’ cord. actually two, I made myself. 34 ft and 42 ft.The wire I used was MilSpec 12gauge silver plated, Teflon insulated 600V in quad twist (so two wires for each plus.minus) wrapped with Teflon tape. Then two solid 2 gauge ground wires between the two quad twist sets. all wrapped in another set of Teflon tape. The whole is about the size of standard Romex. (at 9 gauge equivalent) At the wall, I use a pair of Furutech ’28’ Rhodium plugs into a Furutech GTX NCF Rhoduim Duplex.
At the equipment end, I have them split, one quad goes into a small electrical box on the floor with one duplex, then the wires out to a second box on the floor with twin duplex. This set powers my two conditioners and a few bits like the wall wart for a TT.. The second longer quad goes to the amplifier. where it too is ending in an electrical box with two duplex, one Furutech GTX-D gold, the other Furutech GTX NCF Rhodium So I can plug the amp in either as I please.
So this is just my choice for stuff I used to make my own extension cords.One device you can use to ’clean’ a bit is something like the PS Audio "Noise harvester" (currently a few places are selling them for $50 each if you buy at least two of them, which is a good deal as they list for $100 each) You can plug them into unused outlets around the system. There are others, more expensive, but they also do a better job, unless multiple PS Audio gizmos are used.. So it is a tradeoff.
The boxes I used are just in wall types that look like a box. Made for a duplex or two.You could use common bulk wire from a hardware store, or more fancy wire. Your choice. I used to use common heavy duty Pass Seymour duplex. for years. Only recently went up to the fancy AC duplex.
