I am using the THX onyx the last 2 weeks .( Thanks to Ichos recommendation) .
And I really wonder how is it possible to sound something so small so good ? Honestly it sounds better ( to me) than all that I have desktop or portables dac amps like nano ,micro ,zen,btr5,k5 pro , it sounds better than my big Harman Kardon.
Connected to PC via USB 3.0 it has so much power even my Sundara sound great on that little DAC amp .
Again thank u Ichos great choice.
I'm having the same experience with the Fiio Q3 THX-AAA, I just can't believe how good the 4.4mm output sounds. I believe the highs are better on this Q3 than the BTR5 which apparently has harsher less pleasing treble. Even low gain is plenty for the Sundara and hd6XX.