‘Problem is my vast Spotify library. I’d like to use listen to that also even though Spotify is not all that resolving.’
If you don’t have any plans to switch to Tidal or Qobuz, then Bluesound Node 2i offers a simple and economical plug n play solution. Use its Coax output to your Esoteric DAC. It will also afford you the opportunity to try out the Qobuz or Tidal high resolution streaming.
IME, buying a better streamer (Lumin, Aurender or Innuos) would only make sense if you plan to switch to Tidal or Qobuz. Their SQ in CD resolution is superior than Spotify. I have owned Sonos Connect, Bluesound Vault 2, Aurender N100H. Both Connect and Vault 2 are pretty good streamers but their limitations were glaringly evident when compared with a high quality streamer like N100H.
If you chose to step up to Node 2i, stick with Spotify. Once you experience the Tidal or Qobuz streaming through your Esoteric DAC, chances are you be itching to try a better streamer 😊