Clem, I have an HD800 incoming. I'll let you know. I did give a brief listen to the combo at the SF meet and I thought it was pretty solid. Marv and Anax agreed unless I'm mistaken. There are a few other good cheap-ish tube amps around the Torpedo's price though. Valhalla2 and BH Crack + SB come to mind. A more in-depth comparison would be needed to eek out the champion.

BTW ultra, love the new avatar 

Looking forward to reading your thoughts!

Let me say this about the Torp+800. Good to tonal synergy so pleasant to listen to. On the micro stuff it is a bit congested which negates the strength of the HD800 IMO. I know OJ is playing with different caps to improve this but last I heard the Vali did better in those areas.

Any way you cut it, this amp leans to the warmer side. I've tried 2 different coupling caps (cheaper polyprops at this point) and 6 different tube pairs and none of them (except one perhaps) makes the modded HD800 unlistenable. You can take that for what you will. It's not a dull and smoothed over sound; in fact it's quite dynamic and can definitely bite with the HD800. Although this amp doesn't lie to you, it's not an analytical sound by any stretch.

Tonally it's spot on with HD800. Perfect synergy there. Stage is also quite wide. Comparing directly the ECZD it doesn't quite dig as deep into the mix and it isn't quite as spatially satisfying. ECZD seems very good at placing images in the headstage. But the ECZD has some other overt problems which make me less inclined to listen to it. From what I remember of the Vali, it leaned toward a brighter sound too. Haven't heard it with HD800 but something tells me I might find it objectionable. Keep in mind I have lower tolerance for brightness due to my preference in listening levels and musical inclinations.

Anax: You've only heard the Torp with the gamma2, and surprisingly enough, it does become the limiting factor. The Hilo is a better match tonally and lets the Torpedo show of its technicalities a bit more. I hear an improvement in low-level rendering with the Hilo into the Torpedo which you might like. Other than that, we'll see what a more expensive cap can bring. But this is pretty much where I get off in terms of HD800 amplification. I'm able to tailor the sound well enough by switching out tubes and the hi-lo Z switch offers some extra flexibility WRT different music and mood swings.

For all the blue whales out there chasing that plankton:

Which caps are those?

Claritycap SA series, 630V 4.7uf.

I love this little amp.

I have the Clarity MR's in 10uF for both 630v and 400v.  Definitely a distinct timbre.