Why do I need a switch?

Hi Curiousjim, your sound will be as good as what is feed to your streamer. Noise is the enemy here.  Reduce it and hear so much more into your music. 
 

Cost for all I mention depending on new or used is $900-$1400 or so.  

You will get better sound. Get a decent switch like an English Electric 8 switch. Run your cat6 into it. Place the switch near your rig so you can use a nice Network Acoustics ENO ethernet cable into an ENO passive filter up into your server. Your system will sound much, much better without a doubt. You can try these pieces with a 30 day trial and hear for yourself what you are missing.

You have not heard what your digital streaming front end is capable of yet. One caveat. Your streamer/server needs to be good to realize the improvement. Not sure if the Node is one or not. I have not heard it.

The Network Acoustic products are the real deal and easy to use.  A $40 switch will not improve your sound on its own.  In fact, it may well add more noise and sound worse.  

I keep reading about this fiber conversion step and it has me scratching my head vs the Network Acoustic passive ethernet options. Been there and done that with fiber and the NA passive filter and cables easily surpass the sound quality of the fiber gymnastics options IMHO.  I suggest trying the Network Acoustic options as they have a nice trial period.  You won’t be disappointed if your system is reasonably resolving. The Muon filter and network cable did wonders for my digital streaming.  I have moved up to the Muon Pro and think it is well worth the investment.