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

Shirley you jest.

As Leslie Nielsen said in the movie "Airplane," which I'm sure you've seen, "don't call me Shirley" :-)

BTW, I agree with everything in your post.

Regards,
-- Al 

@Buckhorn_Cortez, if you are referring to one of my earlier posts, I did not say that photons travel **through** wire. In fact I said that they don’t, aside from those corresponding to the small amount of energy that may be absorbed by the resistance of the wire and converted to heat. My basic points were as follows:

(a)In the case of electrical signals or power being conducted via wires, energy is conveyed via an electromagnetic wave. That is why the energy can propagate at near light speed, even though individual electrons move at vastly slower speeds.

(b)In the case of electrical signals or power being conducted via wires, the electromagnetic wave propagates **outside** of the conductors, aside from the slight exception I mentioned above. That is why propagation velocity is affected by the dielectric constant of the insulation surrounding the conductors. Also, if the energy of an electrical signal or power was not conveyed via an electromagnetic wave propagating outside of the conductors, transformers wouldn’t work.

(c)All electromagnetic waves, not just light waves, are comprised of photons.

Also, as indicated in one of the references I provided, photons exhibit properties of both waves and particles. I’m not familiar with the double slit experiment you mentioned, but I suspect it involves their wave properties.

Regards,

-- Al

The concept of a dielectric conducting any signal in the audible spectrum of 20-20hz is ridiculous

What I said is that the electromagnetic wave associated with a current propagates essentially outside of the conductor, and therefore propagates via the dielectric. I was NOT saying that the "current" itself, as conventionally thought of in terms of the movement of electrons, is conducted by the dielectric. Please re-read my posts and also the Wikipedia writeups I referenced.

Regards,
-- Al

The problem I have with the thrust of Al’s post is that he seems to be making the argument that the audio signal - I.e., the electromagnetic wave, the photons - is independent of the copper conductor and only depends on the dielectric characteristics. If that were true then the sound would not (rpt not) be subject to the conductor variables of metal purity, type of metal, type of crystal structure (e.g., single crystal, long grain), diameter of conductor, cable geometry, cryogenics, and direction of the wire.

No, I was not saying that or implying that. I was simply referring to the dependence of **propagation velocity** on the dielectric. And I was doing that to support the fact that the electromagnetic wave, which is what conveys energy and propagates at near light speed, propagates via the dielectric, not within the conductor.

As I said earlier in this and other threads:

... energy is being transferred ... in the form of an electromagnetic wave comprised of photons that is distinct from although intimately related to the AC current.

"Current," as thought of in the conventional sense involving movement of a certain quantity of electrons within a conductor, and therefore the electromagnetic wave associated with that current, are both affected by resistance, capacitance, inductance, and various other factors including many that you mentioned.

It is debatable how much of the electromagnetic wave travels outside the wire and how much inside fhe wire. Is it 80/20? 50/50?

Putting aside the phenomenon of "superconductivity," the resistance of any conductor is not zero. Consequently if a conductor is conducting a current it will absorb a small fraction of the energy associated with that current, and convert it into heat. The resistance of the conductor will be (or at least should be) such that the energy absorbed by the conductor is extremely small. Since energy is conveyed by the electromagnetic wave, though, photons will carry whatever energy is absorbed by the conductor into the conductor. So photons "travel" inside the wire only to the small extent that energy is absorbed by the wire.

Al seems to be hedging his bet bet when he states the signal DOES NOT travel within the conductor, then immediately says it travels primarily outside the conductor.

I used the word "primarily" for two reasons:

1)What I said just above about a small amount of energy being absorbed by the conductor.

2)Depending on the thickness of the dielectric, shielding that may be present, and other factors in the design of the cable some of the signal energy may propagate outside of the dielectric, in the air.

... this thread concerns power cords so it should be pointed out that there is no “audio signal” involved. Which begs the question what is the “signal” traveling down the power cord? Is it also an electromagnetic wave, like the “audio signal,” or is it something else?

I was using the term "signal" to refer to the electromagnetic wave corresponding to electric current of any kind, that is being conducted via wires. Including AC power.

Regards,
-- Al

Although photons are most commonly thought of in the context of light waves, which are a form of electromagnetic wave, they comprise all forms of electromagnetic waves. As stated in the Wikipedia writeup on "Electromagnetic Radiation":

In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.

However, in contrast to assertions Geoff has made in some past threads, in the case of electrical signals being conducted via wires the electromagnetic waves which convey the energy of those signals from source to destination, and which are comprised of photons, and which propagate at a substantial fraction of the speed of light in a vacuum (in contrast to the vastly slower movement of electrons), DO NOT travel within the conductors. They travel primarily within the dielectric (i.e., the insulating material) surrounding the conductors.

A consequence of that is that the propagation velocity of signals being conducted by various cables depends mainly on the "dielectric constant" (aka "relative permittivity") of the insulation that is used in the particular cable, the variation typically being within a range of 50% to 95% or so of the speed of light in a vacuum. As stated in the Wikipedia writeup on "Velocity Factor":

In electrical cables, the velocity factor mainly depends on the insulating material ....

VF equals the reciprocal of the square root of the dielectric constant (relative permittivity) ... of the material through which the signal passes.

Regards,
-- Al

For the record, a minor correction to Azbrd’s post just above, with which I suspect he will agree: "1/60th" should be "1/120th," i.e., half of a cycle.

Regards,
-- Al

Any frequency other than zero Hz is AC, in that the direction of the current alternates at some rate. Digital signals and analog audio signals both contain a mix of many non-zero frequency components that are simultaneously present. Certain digital signals may have a significant DC component in addition to their AC frequency components, an example being USB signals which have one of their two voltage states at or near zero, and the other at some positive voltage. But a signal having both DC and AC components is nevertheless "operating in an AC circuit," it seems to me.

So the only audio-related cables I can think of which are "not operating in an AC circuit" are cables conducting the outputs of DC power supplies that are external to the component being powered.

Regards,
-- Al

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