I've barely listened to the HD-800 on solid state, but have been going back and forth between the Zana Deux and Si2A3. I've
barely been home lately, so I haven't gotten in as much listening as I'd like.
But yes, the HD-800 does mate well with the Zana. I think IpodPJ didn't like the combo, but I'll work on him at the meet next month.

I think synergy is pretty good, and the Zana has a low 12 Ohm output impedance (thanks to the 6C33C tubes) which makes it pretty special for an OTL.
I have to say that the HD-800 really emphasizes the differences between amps. The only other headphones I have with that microscopic pickiness are the SA5000 and the DT48. Interesting.
I'll poke around with some more amps, but I can say that they do well with tubes. If you're a tubehead, be sure to consider the options.