Can a power cord increase the resolution of an Class D (SMPS) amp by more than 5% ?

@geoffkait 
Well, since I don't want cables that act like diodes, I'll avoid their garbage at all cost. 

@mapman 
Sound like real bad in-rush current management. 

@geoffkait 

"You’re right about one thing, the AC current does travel in both directions. But only one of those directions is audible. See if you can guess which one. A prize for the right answer."

The answer is both. How else do you think you build a bipolar power supply? It's the negative phase of the AC waveform pulling half the secondary negative. 

@geoffkait 
No... That's a fact you can measure. I though you'd come up with a better snake oil argument than your old "straw man" jazz. Weak sauce, son.