Lifted from the first line on Empirical evidence - Wikipedia:
"Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure".
To be fair, @jrimer would you not need "empirical data" to prove your contradiction? i.e.; that a power cord makes a difference, or in your eyes, does not make a difference?
If you purchased an aftermarket cable from Pangea and experienced a cable fail, I can see how you would be skeptical. Not only did it not make a difference; but it failed miserably! I can understand your consternation going forward with any further power cord purchases. Failures happen inexplicably. I had an electrical outlet on the wall work and then suddenly! not work. No surge; nothing! Flipped it out for a new one and trashed the one that failed - like you did with your Pangea.
I can attest that blind tests are flawed. If you tell me your gonna test me, then I get excited and that pretty much blows the result. However, if a blind test includes my stereo that I listen to 3-4 hours daily, then I can pick it out of a lineup every time. So can my wife, which is "empirical data" in my world.
I guess if I had to do better to provide "empirical data" on this matter, I would point out that there are many cable companies making many millions of dollars. Audioquest revenue is $14 million a year and started in 1980. The industry has escalated in the past 10 years due to the fact that IEC sockets replaced captive cords in most higher end gear that would benefit from a third-party cord.
This started, in earnest, in the early 90's just after McIntosh was sold to Clarion. I know Roger Russell had a lot to say about this matter (he and Gordon Gow were staunchly anti-cable because it could not be measured) in his memoirs, but he did in fact notice an audible difference in using 4 ohm speakers to 8 ohm speakers and attributed it to the need for less resistance, or bigger AWG cable. So that means that you too should hear a difference if your speakers go below 4 ohms and you have a 3x16AWG cable and then drop down to a 3x12AWG -similar to what he did:
When I (Roger Russell in the 1980's) took the test, I was unable to hear any differences using several different 8-ohm speaker systems. BUT, when I deliberately played one particular 4-ohm speaker and I switched to the line cord position, I could hear differences. I knew this system dipped down to 2.6 ohms in one frequency range, and 3 ohms in another. It verified that differences can be heard if the wire is too light for a lower impedance system. A system this low in impedance requires heavier wire. After replacing the line cord with a heavier line cord of equal length, differences could no longer be heard.
While Roger was able to detect this resistance of the speakers on his scope, the "audible" difference was not measured in any way. Empirical evidence in this regard is not scientifically measurable..either way..but there was an audible difference nonetheless.
In any regard, I wish you luck and urge you to try a cable that other Mark Levinson folks can attest. Your amplifier would most certainly be better for it and most cable manufactures will allow you to try one and return it - no questions asked - if you don't like it. I purchased a McIntosh RCA interconnect on Crutchfield and had 90-days to return it, so burn in was no issue either. There is zero risk involved; all you need to do is listen! 😁
