ETHERNET CABLES

Ethernet connections have an isolation transformer at each end; however, Cat 8 cables are shielded and can transfer noise via the shield from one component to another. That is not true of Cat 5e, 6, or 7, any of which has rated bandwidth far exceeding what's needed for home audio.

I second the recommendation for cables supplied and tested by Blue Jeans Cables. Though personally, I’ve never found any significant differences in sound when switching Ethernet cables -- except for one that failed completely. That was a difference -- no sound!

Thanks Mike, I appreciate your feedback. I will need a 35' to 50' length so that is why I am questioning whether it's worth to buy a higher quality cable.

Didn’t try bluejeans for ethernet but liked their 4974R 12G sdi cable as an SPdif cable.

For ethernet I started with some throwaway CAT5e scrounged from work but later tried some belden 1305A CAT5e and 1303E CAT6a from Designacable in the UK and was surprised to find I preferred the 5e and liked it enough to stop looking.

Ditto on the bluejeans cat 6 ethernet cable. Also using the small green computer optical isolation bundle to clean it up. At first it was a subtle improvement but after a while  experiencing with it on or off, I feel it clearly cleans up the sound, better clarity and space. 

I just bought 4, cat 8 cables of various lengths from Amazon. I had cat 5 cables that I made years ago and one of them started acting up is the only reason I replaced anything.