Cavalli Audio Stacker 2
Ah, there is the exact beauty of not HAVING to own JUST one. Heck, I can't even stay decided on electrostat or dynamic (well, for dynamics or orthos).
In short, no idea.
If you want this to be true: log off, leave, and never come back.
Does it have to be a headphone amp or can it be any amp ? I really like a number of tube amps (mono blocks only) but if I had to pick it'd be a toss up between a set Atma-sphere MA-2 Mk 3.1's or the big McIntosh 2301 tube amps.
I've been using the Woo 5 for about 2 years and to me it's perfect. Plays headphones with the thick full tone that I want, killer tube warmth, wide sound stage, plays efficient speakers too and it looks like a work of art with the extra 35 pound seperate power supply unit. It's my main lover that I'm married too.