Devialet Expert Pro Optical fiber

I have following set.
MAC(Roon) -Wifi router-RJ45 cable-Devialet Expert pro-speaker.
It works perfectly good.
Now I try to isolate and have a better signal , I changed as below:
MAC-Wifi router-RJ45-media converter -optical fiber-media converter-RJ45-Devialet Expert
As soon as I put optical fiber in between, it doesn’t work.Any suggestion?

For example, when I put Mytek bridge(DAC) before Devialet, it works.
Media converters are: Sonore optical module deluxe and 10 GTEK.
For your reference, I have Dela Router S100, which is equipped with SFP , so I tried below too in vain:
Mac-S100-optical fiber-Sonore optical module-RJ45-Devialet Expert

I cannot help with this media converter problem but would suggest to use the same setup like me: MAC/PC - WiFi Router - Devialet Expert pro.
With my tests Devialet WiFi has the same sound quality as Ethernet if not even slightly better. With the second media converter you bring in power line connection so its still not really isolated. To have WiFi work without any troubles i have placed my WiFi router nearer to the Devialet, if this is not possible for you, you could use a second WiFi router in bridge mode, in this case you could even have a WiFi channel exclusively for the Devialet.

Tks for your advice. Yes I sometimes use only Wifi to run Expert Pro.

To Joe. I have a fundamental question . In case we use Wifi only between Mac and Expert pro, where is the DAC function , in Mac or Expert Pro?

Some FMCs are unable to autonegotiate between 100 and 1000 speeds in the same way that virtually all regular Ethernet ports do. So check that whatever FMCs you have are compatible. Also, check that the SFP modules you are using are compatible with the device into which they are installed.
Have you tried connecting any other devices than the Devialet to see if they will work?

Thanks. Following system does work:
MAC-(RJ45)-Router (S100 Dela)-(optical fiber)-Sonore optical module-(RJ45)-Mytek bridge(DAC)-(audio cable)-Devialet Expert (AMP).

By the way FMC mean routers and other devices like optical module, converter?

I use fibre optic from an Innuos server to Devialet Expert. I use two standard TPLink media converters that cost about $25 each. No problem at all.

to your question: every source goes through the DAC of the Devialet Expert, there is no way to use the Devialet without using his DAC. This is not true for digital inputs only, but even analog inputs go first through the Devialet ADC before they go through the Devialet DAC.

In the case of using an optical part with Ethernet you just change the electrical noise from your router/switch with the electrical noise of the media converter, this can maybe less noise depending on the quality of the media converter and his power supply, but you still have no electrical isolation like with WiFi (if this can be heard at all:)

FMC = fibre media converter