Cause of different sound between dacs

A lot of things can make DACs sound different. I order of effect, most first:

1) master clock jitter or interface jitter
2) power subsystem differences
3) D/A chip used
4) I/V (current to voltage) circuit
5) output drive circuit - op amps or discrete, tubes etc..
6) number of stages ie. gain, I/V, drive, volume control - less is better
7) trace lengths on the circuit boards versus point-to-point wiring
8) ground-plane integrity on the circuit boards

Steve N.
Empirical Audio

1. Jitter
2. Digital signal processing
3. Analog circuitry (including power supply).

Look inside. No two are exactly the same. They are all different. Only question is how similar or different any two are.

If you ever try two brands of vanilla ice cream, that taste EXACTLY the same, they probably are, ie same stuff under a different label. That happens on occasion with audio gear (exact same product marketed under two different brands) but not often.