Power Cables

Great. Now that you've written all of that, explain to us how this makes a single iota of difference when in an amplifier's linear power supply the current through the mains is only directly in use 5 to 10% of the time since the power supply system's inherent design is to fill capacitors that provide smoothed and constant direct current for the supply rails that ultimately amplify the signal. Unless your contention is that the current provided by a scant meter or less of cable has somehow conditioned the wall current in such a way for storage in the system's res capacitor(s) that it is improved in some way that impacts what exits the system to be reproduced by cones. That's one magic sonic loogey you got there!

Considering you can get everything you need to build a custom 2m, highly conductive, heavy duty power cable, including high grade, 10g or 8g pure copper, insulated cable and quality silver or gold plated ends, for about $45.00, from any of several industrial, electrical supply companies - the idea of spending $2,000.00 or even $200.00 for a power cable seems a bit ludicrous
The idea that manufacturers like ARC, Ayre, Cary, VAC, etc, etc would build $10,000. amplifiers that wouldn’t/couldn’t sound really good unless the buyer replaced the stock fuses and power cord with special blue fuses and a magic $2,000.00 power cord - is even more ludicrous......Jim

My take on the (no) special cord needed, is more like the amp or device sounds great with a stock wire. However it can sound a little better with a better cord. As for my take on 'how' the last few feet of wire can (miraculously) 'fix' miles of wire errors... The power is a sinewave. Which can be damaged by the endless breaks and fractures in the crystal structure in the common poor quality (compared to high end copper) copper conductor. In those last few feet the wire is cleaner copper, and better structure in the metal. During the transition of the power through that area, it DOES become a more coherent stable waveform. smoothing itself out. Tightening the waveform itself.  From my various power conditioners, they seem to focus the wave, vs the ragged base line power from the wall.Cords seem to do the same thing......     
I have no science to prove this, but it is what I imagine. could be the reason the cords can work.But I also find longer (less than top dollar) powercords do better when they are longer. And this reinforces my suspicion that the reason I offer is the correct notion.(I do not know about the best powercords and length, since I never used any)

There is no doubt in my mind that power tweaks (circuit, outlet, cable, conditioners, etc.) do make a difference to the sound of the amp. And the direction of improvement is always toward the higher priced tweaks. I can say this from personal experience.
This is not delusion yet it makes no sense ... to the pragmatic audiophile ...nor, I suspect, to the design engineer of the amp or the tweak.
I think we just don’t know enough about electricity (nor reality). Personally, if we are living in a simulation, some alien joker coded: IF {’snake oil audiophile fix added’} THEN {’make music sound better in brain of listener’}. That’s my guess.

@dmance I think there might just be a lot of truth in all of that....Jim