Ethernet Cables, do they make a difference?

Sorry, did I insult anyone? For what ever reason on this thread I certainly got slapped in the face.

Absolutely no. I'm a former software engineer with experience in networking for many years. The data that's being delivered in a CAT/5-6 cable is DIGITAL!! It's a stream of binary data NOT analog  data. Ethernet uses CSMA/CD (Carrier sense multiple access with collision detection). If the digitized signal being transmitted isn't 100 perfect it will retransmit the packet. The ONLY difference between CAT/5-8 is the speed at which it's certified for. 10, 100 or 1000 Mbits/s. For a 20-20kHz digitized signal  CAT5 is more then adequate. Again, in the digital domain there is NO difference between a cheap Ethernet cable and a more expensive one. None! If you believe there is your just throwing good money away.

@amg56 thanks for the link, I have learned something new about higher catX cables.
Different cables are designed for different speeds and in the network architecture cable should never be the weakest link.

Designing a network you should look onto the performance of the end components and use cables appropriately.

What may really make difference is shielding but not for the quality of the audio but for the presence/absence of noises, induced in the analog components.

@kosst_amojan actually I used audio over Ethernet cable in my house. There is a protocol called A-bus, it uses special hubs and some receivers have A-bus outputs.
Unfortunately it is not compatible with LAN as we know it and it is not a high quality audio.

It seems to me that what has been largely overlooked in this discussion (with the exception of the brief post by Markalarsen) is the fact that 100% of the energy of an electrical signal, especially one that as in the case of Ethernet contains spectral components at very high RF frequencies, does not necessarily go only where it is supposed to go. Experienced designers of high speed digital circuits (of which I happen to be one) will recognize that.

And given that a number of members here who are highly respected and highly experienced audiophiles have reported finding that the choice of an Ethernet cable can have significant sonic consequences, I offered the following hypothesis in the "Most Important Unloved Cable" thread that David_Ten linked to in his post early in this thread:

Almarg 3-27-2017
Most likely what is happening is that differences in the characteristics of the cables, such as bandwidth, shielding, and even how the pairs of conductors that carry the differential signals are twisted, are affecting the amplitude and spectral characteristics of electrical noise and/or RFI that finds its way via unintended pathways to unintended circuit points "downstream" of the ethernet interface in the receiving device. "Unintended circuit points" may include the D/A circuit itself, resulting in jitter, and/or analog circuit points further downstream in the component or system, where audible frequencies may be affected by noise that is at RF frequencies via effects such as intermodulation or AM demodulation.

"Unintended pathways" may include, among other possibilities, grounds within the receiving device, parasitic capacitances, coupling that may occur into AC power wiring, and the air.

What can be expected regarding such effects, however, is that they will be highly system dependent, and will not have a great deal of predictability.

Regarding the OP’s specific question, though, I would expect that an Ethernet cable that is upstream of his PC would have less chance of making a difference than one that is directly connected to an audio component, where it would presumably be more likely to couple RF noise into sensitive circuit points within the audio system.

Personally I don’t have an Ethernet connection in my audio system, but that’s my take on it.

Regards,
-- Al

@markcooperstein there is one difference - cable look really, really cool.
This thread convinced me to make one really good looking cable, I shall order the best looking TechFlex, cover my Cat6a and - I’ll feel so good.
And I promise I’ll report back here if my sound is better.

Stand by...