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

Two DACs can sound identical just because you are using a poor quality preamp or any active preamp at all in the system. These can totally homogenize all sources.

I don't use any preamp, active or passive. Makes a world of difference.

If you must use one, use a passive transformer. Requires the DAC to have decent output drive though...

Steve N.
Empirical Audio