Any advantage having a 3V Dac output? I understand that a 3V output would be an advantage if one is using a passive preamplifier
Correct, you don't need any more voltage gain from an active preamp,
And you only even need 2v from the source as most power amps only need 1v to1.5v to get full wattage output {clipping), 3v will blow their heads off.
Cheers George