Why do I need a switch?

@jjss49 - Good point about having a LPS after the fiber conversion. I believe the OP’s intended set-up involves only a short fiber cable so both power supplies will be located near his system. If LPSs are not going to be used for both converters, then it might be helpful if the dirty side SMPS can be on a different circuit from his audio equipment, or at least not plugged into the same power conditioner (could try it both ways). BTW, the linear supply I linked in my earlier post (25W DC Linear Power Supply 5.1V 3.5A) is currently available on Prime with free returns. The OP should confirm his converters will operate on 5v since some do but others, like the converters I linked, require a 9v supply, which are not as easy to find as the more common 5v.

Finally, with all of this stuff, IME, do not expect dramatic improvements or changes in what you hear. For me, these ancillary items have resulted in subtle changes at most.

@jjss49 to do this assessment correctly you should have a well filtered or linear power supply on the ’clean’ side (receiving end) fiber media converter... otherwise, the noisy power supply there puts the electrical hash right back in ... before the dac gets the bitstream, thus defeating the purpose...

I added fiber to my system using the supplied switching supplies and could hear a clear difference. I then added a LPS on the streamer end to complete the setup. I think he is safe taking things in steps.

This might be worth a look: https://ifi-audio.com/products/lan-isilencer/

@mitch2

yes indeed, a simple lps for the ’clean side’ fiber receiver is not much money, and can also be bought on a refundable basis, if one does this smartly

just want to make sure when an experiment is run to learn whether a desired effect can be achieved, that it is not self defeating at the outset...

@curiousjim Proceed with caution.  You should research the technology at multiple difference sources before you spend a bunch of money.