Size attributes aside, I reluctantly packed up my XDA-1 today for return, as it just didn't have enough gain on the analog line outs for my Alesis>HiFiMAN rig.
There is no line out mode on the XDA-1, but attenuated all the way up at 80 with my amp all the way up past 5pm it still didn't power the headphones properly. It was slightly better single-ended than balanced in this respect, but nowhere near adequate for my amp in either mode.
Using the balanced Matrix Mini-i in line out mode (no attenuation) for comparison, I listen to my RA150>HE-6 rig at about 10:30am on the volume pots. This is about the same as the level that I get out of my Devilsound v2 DAC cable, which is how I usually listen to this rig. My Mini-i didn't fare quite as well in attenuated mode, but it was still adequate and much better than anything I could get out of the XDA-1. Single ended with the Mini-i yielded pretty much the same results as balanced.
This was the opposite of what I had feared, as the reports of excessive volume on the earlier models are what prompted the new "logarithmic" volume control programming. I may call Emotiva again to clarify, but from their explanation it sounded like they had it originally set up with a linear volume control to go with balanced amps made for studio/pro-audio use, and balanced amps made for home/audiophile use want less gain. My Alesis is made for pro audio use, so evidently not for the XDA-1.
This explanation is confusing to me, as the Devilsound DAC cable and the Matrix Mini-i are clearly made for home/audiophile use. I would like to see if one of the original models with the linear volume settings would work with my amp, but I don't want to risk another round of expensive shipping charges to my location.
Please note that the above comments are regarding volume output levels only, as I couldn't get the XDA-1 to output a loud enough signal to compare it's actual sound with the other DACs fairly.
It's too bad, as I had high hopes for this combo 
Edited by grokit - 2/24/11 at 4:00pm
