Folks, I would like to attempt a build of a tube headphone amp. I listen to headphones quite a bit so it makes no sense to run the whole big amp to do that. Also, I just discovered tube sound with a Heathkit AA-121, and I am not going back to solid state... So, where do I find a kit for a nicer tube headphone amp? I head stuff for $50 has drawbacks, so I might as well spend a bit more and get something without compromising. Any help will be appreciated.