Fiber or Eithenet

I tried fiber optic converters and didn’t like the sound with Bricasti M3. Going copper without switches and converters to me sounds best.
I use EERO mesh network and a short run of good Ethernet cable (1m Purist Audio) from EERO node to streamer.

Fiber works for me, but it terminates into the fiber port in my Sonore Sig Rendu SE Opt. so there are no converters near my system.  Even when I used a converter for the final fiber endpoint, I never heard any detriment to using fiber.  Plus, I know of no "audiophile approved fiber" yet so no need to worry about having the latest and greatest version.

“I guess I’m asking if I should convert to fiber at my switch next to my router, run 50 feet of fiber and convert to ethernet just in front of my DAC or run 50’ of ethernet and convert to fiber and then back to ethernet just in front of my DAC.”

@testrun

Avoid conversion back n forth. If I have a choice between ethernet cable or fiber, I always pick ethernet cable based on my comparison. Fiber or ethernet, best way to settle this is to buy both and listen in your system. Keep the one that sounds best to your ears.

What @soix stated is a reasonable approach, I do think you need some isolation and I will tell you why. I recently moved to a new room away from my router, and as a quick solution while I debated running cables, I bought a TP-Link extender with an Ethernet port and used that. One day I decided to see how a hardwired link would sound and I ran my 30’ Blue Jeans CAT 6 cable across the floor between rooms. This had significant negative effects on sound, I was quite surprised. You might try the extender approach before you start running wire. 

Yes I am running all fiber and using cat8 between the switches. I am fiber copper fiber. With Quality media converters and SFP like you have in place you will not have any sound quality issues. Some have issues by using cheap Amazon converters and SFP. With CAT8 it is shielded at both connectors and can cause your cable to become and antenna for RFI and EMI, that is why I have a drain by un shielding the downstream connector, no transmission into my streamers or switches.