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

Kenny, no, Geoff's statement that only one direction of the AC current is audible is completely incorrect.  As I said in one of the recent fuse threads:

... when AC current is moving toward the component in the "hot" conductor it is moving away from the component in the "neutral" conductor. And vice versa. So it is moving both toward and away from the component at all times. And a mains fuse is in series with the current in the neutral conductor as well as being in series with the current in the hot conductor, via the primary winding of the power transformer.

And simultaneously, as I'm sure you [Geoff] will agree, energy is being transferred unidirectionally, toward the component at all times, in the form of an electromagnetic wave comprised of photons that is distinct from although intimately related to the AC current....

I will have no further comment on this matter.

So if in fact Audioquest's control of the direction of the wires in their power cords provides any benefit, it is not for the reason Geoff stated.

Best regards,
-- Al
 

Al, what I’m afraid you don’t understand, is that both wires are directional. Both wires should be controlled for directionality. Which is obviously what Audioquest does. Nice try anyway. Then you will hear the effect of directionality, because the audible direction for both wires will be toward you the listener. We don’t care what the wire sounds like in the opposite direction. I don’t think I can say it any plainer.

Al,
Thank you for the clarification and I do understand both of your points of view but I’m still curious and I’m going to order one to compare.
If I like it better than what I presently use I will keep it,if not it will sale.Proof will be in the listening comparison for me.

Just curious,
Kenny.

Last time I checked there was only one way to connect most all power cords. So that kind of makes directionality a moot point. You will never know if sounds better the other way or not. I would not loose much sleep over this personally but fret away if one must.  GK will be glad to help I'm sure.

Moops checks in with yet another silly comment, guess he’s bored and figures, what the heck, at least he can boost his already astronomical post count. Obviously the whole fabrication process must be controlled to ensure directionality is correct. Not only for speaker cables and interconnects but also power cords and Ethernet cables and HDMI cables. Hiding your head in the sand doesn’t make the problem go away, Moops. Let us know when you guys figure out what the term directionality even means. 

Pop quiz 
Of all the various audio cables and cords which ones are not AC?