Hi Doc, PJ and gang!
Just a suggestion... I understand that you have heaps of projects on the go, but considering how into headphones you guys are, have you ever considered doing a small portable tubed headphone amp?
As far as I know, the most popular portable tubed headphone amp is done by ALO Audio, but I for one would be keen to see what you guys can do! I'm sure that it's probably even more down your alley than the headphone kit you were considering!
If you do a DIY kit for one, put my name down!
Taz.