My 45 is a custom build designed and built by 2359glenn. As far as I know it's one of a kind and a lot of the design choices, both visually and electrically, were my own personal ones. The tubes in it are KenRad UX-245s, I'd date them between 1928-1930, and they are by a long shot the best 45s I have run in the amp. My 45 is my pride and joy, but like the Inspire it doesn't drive every type of headphone well so it's good to have other amps around for variety. The amp in the middle is an OTL made by the same person. The 6BX7s I bought from a trusted seller, and I believe the were new old stock. The sound is excellent, it's just not very loud.