In playback (like a DAC converting to analog): jitter can smear the timing of the reconstructed waveform, producing subtle distortion or loss of clarity.
There is an important difference between digital music files and other computer data files. This would be time domain errors rather than the absolute correctness of the data file. With music files, there is less time to correct errors during the process of converting digital music files into analog sound waves. As other have mentioned, there is nothing wrong with the music file data; the differences are in the timing of when a binary 1 becomes a binary 0 versus when that should actually happen based on the original recording. There is probably a valid debate as to whether those differences are audible & probably a debate as to whether some people can hear those errors and other people cannot.
My real-world experience listening to ethernet cables including an AmazonBasics Cat 6 cable, Supra Cat 8 cable, and a ethernet cable from a Chinese company via Amazon is that all sounded different.
What I have heard from the Supra cable versus the AmazonBasics cable is:
- More presence to voices and instruments which sound more forward and distinct in presentation
- Richer tonality
- Less grain to the sound
- Better resolution due to a lower noise floor (This is audible when comparing a cleaner signal to one that is less clean)
- Easier to follow bass lines
- Pace seems faster due to more clarity and better definition to the leading edge of notes.
In terms of potential bias in my listening, the Supra cable was something that I could return at no cost. I was interested in hearing:
1. Whether there was an audible difference?
2. The magnitude of that audible difference?
3. Whether that audible difference was worth the $60 that changing to the Supra Cat 8 ethernet cable would cost me versus sticking with the $8 AmazonBasics cable.