Conversations like this always degenerate, they don't have to. Why is there such a powerful desire to prove someone wrong?
You make a good point. If one can have a reasoned civil conversation about test methodology, it should be here. I may have been overly emphatic at the start, and apologize if that is the case. However.... dreite's first post calls the discussion "silly" because Ethan's test was invalid due to using a "voltage source".
Perhaps I do not know what distinguishes a "voltage source" from the media player that was actually used, but this, was in the context of the immediately preceding posts (the links to the PSAudio forum) that are a list in which the Null tests are deemed invalid for spurious reasons. And dreite's 1st post seemed to me to be another spurious objection based on not understanding the test.
Dietre is right that the test as shown in the video does not simulate every real world situation. But, Ethan's device is designed to use ANY preamp as a source...and it is good science to determine the circumstances in which cables might matter. I would be surprised if Ethan would not be open to using different sources, especially those in which there is a possibility cables have an impact. It appears that is exactly why he designed the tester the way he did.
My "Smart Ass" reply was because a scientific determination of whether there are some circumstances in which a cable might matter is not at all what Paul and other cable vendors are talking about.
Rather (and I admit being riled up by reading the PSAudio forum...including several authored by Paul himself that are not reasoned, civil, or valid.) they rely on ad hominem attacks about Ethan's hearing, motivations, and biases. My smart ass vitriol was aimed totally at them, not dreite.