Why do I need a switch?

So the TP-Link boxes are installed and everything seems to be working,  but I really don’t hear any difference. I’ll give it a few more days to break in or whatever and if I still can’t hear any difference, back they go.

So you added optical fiber in the Ethernet chain from your router to your music server?  Anything else between the router and your music server?

And you hear no difference?  Well, I’d say that you should have heard a difference immediately if you were going to hear anything.  It’s likely that it will not change over time.

OP,

Thanks for documenting your experimentation.

@curiousjim 

I really don’t hear any difference.

I am not surprised, and I agree with @tonywinga that you should either hear a change, or not - your perception is not likely to change over time. 

I have gone back and forth with fiber or Ethernet multiple times and as I said earlier, subtle changes at most, to the point where I doubt I could reliably discern the change, if there is any - they both sound good.

I never asked, were you trying to fix a problem or simply exploring possibilities to optimize your digital source?

@mitch2 

All of this started because I read a couple of articles and saw a few videos about cheap switches making a positive impovment in hifi systems.  So in answer to your question, I’m exploring possibilities.  I had a couple Netgear switch's, but for the life of me I can’t find them, so for $67, I tried another Avenue and bought the Ethernet to fiber boxes. 
In the same vein, I have read a few articles and watched a few videos about reclocking. It seems to me that it’s basically the only thing a switch does that could possibly change/improve the signal/sound. So, I was thinking about getting a Denafrips Iris DDC to do the reclocking job, but haven’t made any firm decisions yet.