roon sound wasn't as good

“My server for roon was my pc”

There has been many debates (mostly from IT pro’s aka naysayers, 1’s and 0’s, IP Protocol and blah blah crowd) that running Roon Core on a separate PC, Laptop or NUC won’t matter. They will be here shortly and tell you have been hallucinating. It’s no more a secret that implementation and design of any component that is tasked to stream music near or far on your network matters. 
 

But the server (core) usually matters far less than the player.

Was this over Wifi or Ethernet?  What upsampling, if any was done?

Roon DSP functionality takes a little time to get the hang of but it’s worth it and opens up all kinds of possibilities for tailoring the sound room by room, device by device all in digital domain. I use it all the time and have presets for 4 different rooms and various headphones.

The computer does not matter if you use fibre to get the bits to the DAC. I never connect my computer directly to the USB input of a DAC. Always use fibre to stop all the analog noise from the network getting into the DAC. It is like a moat around the DAC.