Pros: Great Sound
First highend headphones and AMP, so the review will not be technical. Using this amp with HD800's after ALO allowed me to test several high end headphones. ALO was excellent to deal with and the only site in Portland Oregon to have multiple high end headphones and amps. The music is great, as others have stated. Also purchased a headroom total bithead portable amp for work. Total bithead's sound isn't close to the Ultra, but costs are relative and was purchased for portability. At work using the total bithead and Byerdynamic T5P mod by Alo.