And before asking for proof, they would probably start by pointing out some of the obvious reasons why it is ridiculous to think that power cables could possibly affect sound quality. And after you respond to that by insisting that you really hear a difference and are not prone to confirmation bias, that's when they'll start asking how much money you're willing to bet that you can tell different power cables apart in a proper, controlled test where the sound you hear is the only information available to you, by which you would be able to identify which power cord is being used. At some level you have to know that there is no possible way that you could hear the difference in power cords. Just because Fremer says you can doesn't make it okay for you (or anyone else) to say that you can. The power cords that are included in amplifiers and other audio equipment are generally over-engineered to begin with. The wire gauge that is used is significantly larger in diameter than there is any genuine need for it to be. In fact, a 10' power cord made from dirt-cheap 18-gauge lamp cord is perfectly adequate for virtually any amplifier, assuming it has the proper kind of plug at the amplifier end of course, and there is no possible way that you'd ever hear any difference.