Hard to believe all the crap that flows thru an ethernet cable


So apparently lots of crappy stuff needs to be cleaned up from your ethernet cable before reaching a dac.  
And to thoroughly clean it up you are wise to spend $1300 for an optical rendu device, and sound quality drastically improves.  Wow. Sounds like a great deal.  
I guess a really good dac with galvanic stuff going on and strong pwer control needs more help.

do i really need a rendu device? I see it on high end systems so that seems good.
jumia
I connect my streamer to my router with Cat6a cable about 50ft long since the router is in my home office..
Seriously just go wireless to your streamer if you think you have a problem.   I have for years and everything is clean crisp and noise free and no bandwidth issues.   If you have bandwidth issues (not likely with most any recent Wifi gear) that typically manifests itself with streamer having to rebuffer occasionally, if everything is done right and working as it should.
If wireless works, it didn't for me to many dropouts, that would take care of noise problems. Could be a ground issue.