I'll confess, I got my degree in Mechanical Engineering. In addition I am qualified as a Journeyman Machinist so I am a bit rare, I actually know what it takes to manufacture what I design. Which means that I had 2 courses in Electrical Engineering, just enough to have a basic understanding of electronics. However, 110V 60 hz AC power is really really basic.
I recently read a review where the reviewer went on and on about the benefits of a 2000 dollar plus power cord. Magic transformation of the bass drive, etc, etc, ad nauseum. Frankly, I don't think that reviewer heard anything except his expectation that the 2000 dollar power cord "had" to sound better simply because it cost so much.
Why? Simple, 110V 60 Hz power is power, period. No power cord is going to change that.
Lets cover the basics of AC power. First, there is Voltage. That does vary in the home but a power cord will do nothing to alter the Voltage at the amplifier. Second there is Amperage. That is limited by the circuit leading up to the wall outlet and no power cord will change that. Third there is Phase Angle. This is a condition where the Voltage and Current waveforms are out of "sync". Changes in Phase Angle are caused by electic motors or flourescent lights but it takes a LOT of consumption by either to have a significant effect. BTW, power companies routinely audit for Phase Angle because it can make electric meters read "low". Your typical home doesn't have enough horespower in phase angle changing motors to have an effect on Phase angle that would be noticible, probably less than 5% change in the most any of us would have. Third, there is the frequency of the incoming power. No power cord on earth will change that, what you get is what you get. BTW, it's also pretty darn good, those power station generators are hugely massive flywheels and they don't change speed very quickly at all. There may be as much as a 2 hz "drift' in the 60 hz power signal but it's expressed over HOURS and really wouldn't be audible. Last there is Noise, which is probably quite typical in a home environment. However, Noise is so easy, and cheap, to filter out that I would expect that every amplifier made has a very effective noise filtering network built into it's power supply. Most likely, just one 2 dollar capaciter and a small inducter is all that is needed.
So what's left to explain that "magic". According to the web site for the power cord, it provides an additional level of noise filtering. I'm sure it does. Nowever, the internal fiter in the amp probably reduces the noise by a factor of 75 db or more. Suppose that it gives an additional 6 db of filtering. Folks, that is a difference between 0.000000029 and 0.0000000075. Which means that the noise signal that might rob a bit of power from the amp is really really really MINISCULE. I suspect that the difference in noise level is probably well below the measuring threshold of any measuring equipment made.
So what's left to explain the "magic". Anyone remember the Advent Loudspeaker and Henry Kloss? He was my kind of guy, a basic nuts and bolts engineer who had no use at all for the "smoke and mirrors" that is so common in high end Audio. At the time he stated that his speakers really didn't need to produce more that 15,000 hz because no one, except for small children and dogs, could hear any higher. So producing a tweeter that could put out 100,000 hz was just stupid and he wouldn't do it. Know what, Stereophile recentlty did a reprospective review of those Advents and rated them quite highly. Not bad for a speaker built more than 30 years ago without a computer in sight. Guess Henry was right, we really didn't need frequencies we can't hear. Bottomline, these types of components are just "smoke and mirrors". If you really think your gear sounds better with one of these power cords it's only because you don't want to think you spent 2 grand and can't hear anything. It's amazing the capacity for the human mind to "adjust" it's perception to meet our expectations. Just remember that a double blind jury pulled off the street won't hear a damn thing and neither will your mate.
Folks, this is just one example of the kind of "cons" you'll always see in Audio. What amazes me is the reviewers who seem to be perfectly reasonable and intellegent will buy into stuff that any good engineer will tell them is completely bogus. Bottomline, if it's really expensive and the explanation sounds a bit flaky, don't buy into the hype. If you want to give it a try, go ahead. Just make sure you can get a full refund if you don't hear any difference. That's what I do, if I can't hear it, I don't keep it.
PS, for me, high end speaker wire - Hype. 14 gage zip cord sounds just the same. Hi end interconnects, worth it as long as they are reasonable (50 bucks).