True the treble sparkle, liveliness and 3D etc. will depend on the DAC and the rest of one’s gear. My humble impression was in comparison to Marantz PM11 and in my system.
None of them is much better than the other IMO. Master 9 is a bit smoother, laid back, a bit more refined (class A sound, for lack of better word) and have more midrange fullness. Marantz is more vibrant, more 3D, have fuller and better defined bass, a bit clearer overall sound and with more treble sparkle. Treble sparkle is a very tricky thing, too much can make many records less pleasing to listening to. Too little sparks and it can gets a bit flat and boring sounding.
The PM 11 is an integrated amp, so just to clarify are you comparing the sound of the Marantz through the HP out or through the speaker taps (driving the HE 6).