I just got my hands on an Antelope Zen Studio today.. Cool unit.. very easy to use.. I'll be comparing it to a M audio Profire 2626 and Behringer Ada 8200 through an ancient RME digiset that was sold by Steinberg back in the day. So far.. I've just had a chance to listen to some speaker test songs and I'm shocked that the difference in D/A between the Ada 8200 and Zen Studio is the same... I didn't do a test tone.. just level matched as close as I could.. I had to set the output of the Zen to minus 19.. and the Rme to minus .5 To get things as even as possible.. will do a test tone tonight.. I'll also record some drums with all 3 units to see what's up with them.. So far I hear a big difference between the Profire 2626 and the RME/Behringer but none between the Zen and Rme/Behringer D/A wise.... I'm kinda shocked.. More tests are needed.. Any songs suggestions to listen to that would be good for comparisons showing depth and clarity?