rodman99999
the cleaner the power (from the wall, cord, fuse and PS), the more faithfully the resultant signal, when it reaches your speakers for reproduction.
Do you know what EMI filter does and where it's located and how those x/y capacitors and common mode chokes work together to swamp out all EM interference noise that the power line picks up right from the power grid (not just the last 5 feet from the wall outlet) to your audio equipment. Yes the EMI filter should swamp out all RF signal from the power cable so the noise can't make it through the power supply of the audio unit. You just need a cable big enough to carry the current without heating up. And that's why you don't need a power conditioner either to clean the AC power from the wall outlet.
I bought amazon power cables for less than 50 and I love them because they please my eyes. They don't make my audio system sound any better than the stock power cord. What about $1000 power cables? A total waste of money. Nonetheless we all know "placebo effect" is alive and well so you'd believe a $1000 cable/the magic oil lamp makes your system sound better because you feel better about it.