Big source improvement using CD player

Spotify is not intended to have good sound quality...

It's no doubt that a cd player is better than spotify. Try Tidal or Quobuz and the story ends differently.

And no you don't need a USB dac into a computer. Get (at a minimum) a Bluesound Node 2i and computer be damned.

Oz

Puff, you have uncovered a great truth of digital audio: CD playback sounds better than streaming. I have found this to be the case in every scenario I’ve tried: in my main rig, my headphone rig, in my car, etc. 
Of course price and quality play a role. A $15 CD player probably won’t beat a $1,000 streamer. Given comparable budgets, CD players sound better.

Oppo 105D.

CDs sound better than streaming? Shh ... once the word gets out, the streamers won't be donating their CDs to the thrift stores anymore. 

Frank