rudyb
People may hear a difference between power cords, even though it can’t be measured. So what? If someone likes it more, than that’s a given.
That confuses the issue. You've just assumed that people ARE hearing real sonic differences between power cords. But that is under dispute for good reason. It's a doubtful proposition based on how power cords/electricity/most audio gear actually works. Most electronic engineers - the ones who are not trying to sell you those products - will explain that. And the few who DO believe inevitably have only anecdotes for the claim.
Why does this matter?
It matters to anyone who cares about the truth, and who wants to understand how gear actually works. Why in the world wouldn't that be worthwhile? Knowing how things work helps an engineer meet his design goals without unnecessary rabbit holes. Knowing what type of gear or tweak is likely to make a sonic difference helps someone spend their money more wisely. I am VERY happy to have the information being made available by folks like Amir (and others over the years).
None of this forces anyone to care. You don't have to avail yourself of such information. No problem. But there are good reasons other people have for wanting to know whether things like power cords actually alter the music signals.
And to get to the bottom of such issues, you have to account for common bias effects in the process.
Scientific measurements can deduct a certain device measures better than another, and listening tests can deduct a person likes a certain sound more than another. These are two entirely different things, and both can live perfectly together.
Saying objective data and subjective impressions are entirely different things is like a diabetic saying "Look, the way I may be feeling, tired, peeing a lot etc is one thing. Measurements of blood sugar is another. These are entirely different things!"
Well...if you want to remain in ignorance about the correspondence between your measured blood sugar and your symptoms that's up to you. But, no, they are not entirely different things. The correlation between blood sugar measurements and diabetes/subjective symptoms, has been studied.
Likewise, there has been plenty of study correlating measurements of sound to their subjective effects for most people. If that weren't the case we wouldn't have stereo, surround sound, audio codecs, reverb and other plug-ins for professional sound etc. And the subjective effects of various measurable parameters in loudspeaker designs have been studied. As have human hearing thresholds in regards to levels of signals or distortions we can hear.