Why do I need a switch?

I agree @jjss49 

besides putting in the Ethernet to fiber, I’ve also been thinking about getting the Denifrips Iris DDC, but unlike the Ethernet to fiber boxes, the Iris isn’t going to be returnable, so it’s much farther down the list.

Seeing as this is only a test, I just ordered a couple of the Ethernet to fiber boxes from Amazon and we’ll see what happens. If I hear anything I’ll get better power supplies and if I hear nothing, they’ll go back and I’ve shelved adding a switch for now. I do have a cheap five channel switch somewhere, but it can stay in the cabinet for now.

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...

So been doing some reading on credible EE related websites, and I found this interesting tidbit:

While Ethernet is DC blocked by a transformer there is also a 1000-2000pF capacitor around the transformer to reduce common mode emmissions.

I wonder if these Ethernet isolators, like iFi or Tripp Lite or Everstar keep that cap in place?

Look at Figure 2, specifically at C2 and C3.

@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.