Thanks, that helps alot.
The x-can arrived today and I happened to have the 722 and grados at work with me. It sounds very nice. I'm listening to a kate gaffney show I recorded blumleim 414s in spot well ahead of the crowd so it's a really clean recording. The show sounds very nice and airy though the x-can>SR80 combo.
A lot of people seem to dislike the grados but I'm liking what I hear so far - but this is my first HP amp.