Can't believe that I missed this. I did take the LCD-2s in to try for an hour with the SQ-N100, which is an EL34-based speaker amp, but has a reputation for being good with headphones too. I think it would work best with brighter cans such as HD-800s. It was lovely and silky with vocals and the LCD-2s (helped indeed by the Esoteric SACD player I was using as a source) but a bit too rolled off in the top end for them IMO. I am still tempted to get one as a speaker amp. I can't help wondering about the Luxman designers who come up with these designs full of wire -- it hasn't changed since the 80s! Still, $2k is quite a bit better for a Luxman than the headphone amps which new are $3k.
I owned the SQ-N100 before the 505u -- strongly prefer the latter with my Harbeths and various phones. More power, more dynamic; without the sheen of the EL-84 mids, but overall a more satisfying sound to my ears. The 505u has received relatively little attention as an HP amp, but it's very competitive with the lesser Lux dedicated models to my ears. And as a speaker amp, it's a monster.
Edited by orkney - 12/2/10 at 8:22pm