I am trying to track down external sound "cards" that I don't know about. Rather than double-post and end up with two parallel conversations, check this question our over in the Engineering forum:
http://radiodiscussions.com/showthread.php?655146-Quality-USB-A-D-devices&p=5931184#post5931184
http://radiodiscussions.com/showthread.php?655146-Quality-USB-A-D-devices&p=5931184#post5931184