ifi Ethernet Optical Isolator

[ray1234]

Those from FMC (the chinese ones) i coulndn´t find it.

Type in Fibre Media Convertor in Aliexpress, you will find plenty.

Another thing you have to bear in mind, this cheap FMC has very poor transformers that are very noisy. Put the transformers of these cheap FMCs in a separate electric network than the power network for your hifi, otherwise the interference from these cheap transformers is going to mess up your hifi.