Doing my first listen as we speak!
I was impatient and it's 3am so I wasn't able to assemble the box quietly (hammers aren't known for being quiet, yeah?), so I used a copious amount of masking tape to temporarily hold it together while testing.
Mids are definitely lush. Reminds me of my HD595 + LD II++ pair I had. Only with better bottom end and better soundstage.
At first, I felt I lost some sparkle on the top end, but then again, the HD650's aren't known for being sparkly. I stopped thinking about that, and concentrated on the mids. The delicious smooth and warm mids. Man. Good stuff.
So far, I'm impressed. Have a lot more listening to do though! I don't think I'll be selling my Lyr through. It's still a great amp and I'm sure I'll regret selling it if I ever get an Ortho or something to drive.
Will return with pics and impressions once I get more listening time.
See if you can find yourself a nice 1950's 12au7 Tung-sol JTL they are a little more expensive than the RCA 12au7 clear top but are more refined and resolving whilst still retaining that treble sparkle that the cleartops have that works well when in combination with the HD650.