Sonore Rendu or similar

I used a pair of TP Link media converters.   Has a SFP port that accepts an optical module.  Works perfectly.  Zero noise or problems converting a Ethernet over AC adapter to optical before my network switch 

Boxes were half off on Amazon,   everything was less than $90

You want to convert back from fiber just before the device you want to isolate. So if you have a music streamer like a ultraRendu you want to convert it to fiber Ethernet then back to wired Ethernet. Use a short one foot Ethernet cable to go from the FMC (Fiber Media Converter) to the streamer so it doesn't pick up much noise.

I recommend using a linear supply on the FMC on the clean end of the fiber that goes into the streamer and if you want very good noise reduction use an opticalModule. The opticalModule is a very low noise FMC made by Sonore.