Check out the Perreaux SXH 1 headphone amp. I received mine last week and while it is still burning in it sounds great. Easily drives my Senn 580. You can get it at Audio Advisor for 299.00, catalog price 349.00 just ask for the discount coupon (50.00 off) and they throw in free shipping. Plus 30 day return. I'm not associated with AA. Also quite a few reviews on http://www.head-fi.org/
Robertp50
Robertp50