I have decided: will buy both. O2+ODAC is already here at home and gosh it's great, HUD-mx2 on its way... I like to waste money on nice devices which are different but quite the same :)
Just sold my Modi and Magni stack. Modi was quite worse than my E-MU 0404 USB and Magni had quite high THD with volume past 2 o'clock (needed for 600-Ohm Beyers).
Also selling my Graham Slee Novo right now. Bought in 2009, every year I had it I was realizing more and more what a waste of money it was...
I also realized recently that I could not tell the Magni and Novo (except that the Novo had audibly rolled-off bass with low-impedance phones) from the headphone output of my E-MU 0404 USB. I wonder if in some time spent listening to it I will be able to tell the O2+ODAC and HUD-mx2 (once it arrives) from the EMU 0404 USB headphone out. Right now I feel like the O2, when driven from the EMU 0404 USB, has more dynamic and clearer sound than the EMU 0404 USB headphone out, but I'm not sure I could tell them apart in a blind test.
I wonder how the HUD-mx2 will compare. Considering it has no analog input just for the amp and it is always being driven from the integrated DAC, I wonder how will I be able to evaluate the sound of its amp. Maybe just by using its analog line out feeding the O2 and then switching to the Audinst's headphone out...
Anyway, if I do not forget, I will share my experiences.
Edited by TomKure - 1/16/15 at 9:29am