1. What else is there? Apart from the science and of course the fact that it's demonstrated in practice trillions of times a second all over the planet and has been for years, what else do you think is going on in an ethernet cable, some sort of magic?
2. Ah yes, the old audiophile cry: Dismissing some of the most proven and demonstrated science, without which the modern digital age would not exist, in favour of the sense of hearing, the fooling of which is not just a fundamental fact known for more than 5 centuries but an actual requisite. If our hearing couldn't be fooled, then music (and nearly all commercial audio) could not exist! .... It's easy enough to verify that the ones and zeros coming out of an ethernet network are identical to the ones and zeros that went in, indeed, this verification is effectively built into the ethernet protocol to start with and if the ones and zeros are identical, by definition there is no difference because digital data only has these two states. So if a difference is heard, it MUST be a function of our hearing/perception and cannot be a function of the ethernet cable (or other ethernet equipment)!
Furthermore, there's a second audiophile fallacy in your statement: "
in a decent highly resolving system", which is fallacious for two reasons: Firstly, there is no system that can fully resolve even 16bit digital audio, let alone 24bit, including our hearing! And secondly, it's fairly certain that whatever system you have, it's not as resolving/accurate as the systems that I'm used to.
1. Good you're getting there, you just need to take the next step!
....
Excellent, well good luck with all that and i'll stick to trusting my ears
2. Even disregarding RF and any other electromagnetic interference, there must be noise in every electrical circuit: Johnson/Nyquist Noise (Thermal Noise) is an unavoidable scientific fact that's been calculable for nearly a century. The fact you're ignoring is that this is why digital data and digital audio (and the telegraph/Morse code before it) were invented in the first place! Like Morse Code, digital audio only has two states, zero and one (as opposed to dot and dash), there is no additional state for noise. Either the noise is great enough that the receiving telegraph operator cannot differentiate a dot from a dash or the noise is not that great and is effectively eliminated. The same with ethernet, except that ethernet has sophisticated error detection and correction. What comes out of an ethernet network again has just two states with no noise, because as with the binary telegraph system there is no state for noise and it has therefore been eliminated. So, there CANNOT be a difference in sound quality between ethernet cables/switchers, either the receiving equipment is functioning and reconstituting the zeros and ones without noise or it is not functioning! Of course though, once the receiving equipment has reconstituted those zeros and ones (without noise) we've got to get that data from the ethernet receiver to the DAC chip, which involves another electrical signal/circuit and therefore the addition of at least thermal noise again.
2a. No it's not! The analogue and acoustic components of an audio system are not digital/binary, they do have a state/s for noise, so any noise/interference introduced is NOT eliminated and is in fact cumulative. Which again, is why digital data/binary "bits" were invented in the first place (as proven by Claude Shannon in his "Mathematical Theory of Communication" paper in 1947). If this were not the case, then not only digital audio but digital data in general would not exist, which is why Shannon is often referred to as "the father of the digital age".
2b. It would however come as a complete surprise to Claude Shannon and everyone else who understands the basic principles of digital data/audio. It would also come as a surprise to billions of people to discover that none of their digital devices ever work and don't exist!
2c. Again, no!
ALL ethernet receivers either completely eliminate/reject noise or they don't function, it's just zeros and ones or non-functional, there is no other possible state/condition! However, as mentioned above, once those (noiseless) zeros and ones have been reconstituted in the receiver, we're going to need another electrical signal/circuit transfer that data to the DAC chip, which again means the addition of at least thermal noise.
But it's not "based purely on listening test", you haven't done a purely listening test, you've done a "purely perception of listening test" and as mentioned above, if your perception of listening/hearing could not be fooled then you wouldn't be listening to music in the first place, because you wouldn't be able to perceive music!
G