Most Important, Unloved Cable...

I work in data centers on IP storage (VERY large NAS systems), we do use CAT 6 cable for 1g and fiber optics for 10g, but we never worry about the cable brand.  If you are using 1g and a CAT 5 cable (which is rated for 100mb) you should replace that with a minimum of a Cat 5e cable.

Now to suggest that better sound is possible by changing Cat 5e to 6 or 7 does not make any sense, are Better 1s & 0s transmitted?  If changing a network cable did somehow effect the sound you might want to check your DAC,thats really where the 1s & 0s become sound.

First let me say that all of you are welcome to spend money on what ever makes you feel good, however, the science does not add up.  

What does an ethernet cable do? It caries TCP & UDP packets (which are 1s & 0s) from source to destination, these packets are built with headers & payload/data which is more 1s & 0s.  If packets dont make it to destination TCP handles retrys, if this did not work all of us would have problems with our connections to our network providers.

In a typical TCP/IP stack, error control is performed at multiple levels: Each Ethernet frame carries a CRC-32 checksum. Frames received with incorrect checksums are discarded by the receiver hardware. ... Packets with mismatching checksums are dropped within the network or at the receiver.

So if there are real network issues you get packet loss which in audio is a gap in sound because the DAC runs out of bits to process into sound.  Changing a ethernet cable COULD reduce packet loss, so could a better switch (or current firmware on the switch) but it will NOT change the 1s & 0s (which are what a DAC uses to create audio) to better 1s & 0s.  It also does not matter if the payload is audio or video so the same side effects occur, loss of packets ie 1s & 0s if a cable is bad or not the correct cable for the task.  How many of you stream Netflix or video via Apple TV, this is built on the same tech, for that matter everything on the internet is built on the same thing, TCP and 1s & 0s.  There is no such thing as a better 1 or 0 (a "better" cable) that enables a DAC to create a better sounding audio sound.  

I build & trouble shoot network and data storage issues for a living, if I use the proper cable rated for the bandwidth, ie 1g, 10g or 40g, I do the same for my home network where Stream digital 100% of the time, I build & test my own cables using CAT 5e because CAT 6 wires are so stiff and hard to work with and I only have a 1gb wired network.

+1 dynaquest4, well said!  milpai, have you considered all the $2 cat5e/6 or fiber cables in the path between your system and Tidal or where ever you are streaming from?  Trust me, I have worked in HUGE data centers that move exabytes of data (1s & 0s) around and NO IT guy ever thinks twice about the possibility of a cable effecting sound.  We make the cables, test them to make sure they conform to standards and thats it.

I just upgraded my home ethernet service from 20Mb to 40Mb and had an interesting talk with the installer.  As he was testing the new connections he mentioned all the splices & switches that exist between my home and the CO and the effect they have on the overall performance I will see.  I mentioned the fact the some people believe that spending big $ on fancy CAT 6/7 cables for their audio systems and he laughed & could not figure out how those cables could possibly have any impact on anything.  The real fact is there is so many switches & splices upstream from your home that no single cable could compensate for it, TCP and its built in error corrections and retries is what does that.