D220 pro CI vs D440 pro CI

[chungjh]

I need some advice on D220 pro vs D440 pro. I listen only to digital music (Tidal) from my old mac laptop to USB to D220 pro to Dynaudio confidence C1 bookshelf speakers (4 ohms impedance) (in a very small room 10 ft x 11 ft x 8 ft high). I think the sound quality of my system can be improved but I don't know which is my weakest link. Devialet suggests that I get another D220 pro and make it D440 pro. For that price, I could get a much better speakers or at least ones with less impedance. How about adding a better clock between Mac and D220.

I would appreciate any advice.

thanks