It is quite possibly not actually the digital conversion, but rather the analog stage in the DAC. The analog output stage designs vary pretty wildly in both DACs and players, and range from op amp based. all the way up to fully discrete output stages.
Why does my old CD player sound so much better than my new streamer?
Earlier this year I upgraded my system. Briefly, new Prima Luna Dialogue Premium HP integrated, new Lumin D2 streamer/DAC, kept my Tekton speakers, bought a 10 year old Muse Erato CD player, new Nordost Red Dawn cables all around. After plenty of break in, the Lumin D2 streaming Tidal, even 24/96, does not sound close to as good as the Muse Erato. I understand the Muse was about $10k new years ago, I paid $650 for it on Audiogon, is that the difference? It replaced my Naim I had for 20+ years and I bought it on the chance I want to listen to something not on Tidal, but now I'm going to CDs when I want to sit and listen instead of streaming. I considered upgrading to the Lumin T2, but will that be more of the same Lumin sound, which is accurate but thin and a little cold compared to the Muse. I like the Lumin when just letting Tidal shuffle music as I move around the house, but from the opening note in an A/B test the Muse just sounds so much warmer, live and simply more enjoyable. Any thoughts or suggestions?