Jinjuku 9-14-2017This assumes that all of the circuitry that is involved performs in an idealized manner, meaning that effects of the non-real time signals and circuitry on the downstream real time circuitry are zero, carried out to many decimal places. As an experienced designer of high speed digital and analog circuitry (for defense electronics) I can tell you that is often not the case.
People that are discerning these differences are describing real time phenomena to a non-realtime system of data transmission. It is 100% delusion pure and simple.
For further explanation see my post in this thread dated 3-27-2017.
Also, while my own system does not utilize an ethernet connection, the many posts that have been made here over the years by members such as Grannyring, DGarretson, Bryoncunningham, and others who have reported finding audibly significant differences among inexpensive ethernet cables warrant a great deal of respect for their reported perceptions, IMO. That respect coupled with the technical hypothesis I stated in my 3-27-2017 post leads me to emphatically disagree with your assertion that they are delusional.
Regards,
-- Al