I've had excellent experiences with both "tctubes.com" (Tyler and Chelsea are a pleasure to deal with, and they really know their stuff) and Brent Jessee at “audiotubes.com" who is an expert with all kinds of tubes. I bought two matched quads (four years apart) of Genelex Gold Lion KT-77's from tctubes, and have been extremely satisfied. More recently, I bought a set of five "small tubes" from Brent Jessee ..... a matched pair of GE JG 5751 backplate triple mica premium military grade (12AX7 spots), a matched pair RCA 12AU7 Cleartops (12AU7 spots) and a single Telefunken ECC82 smooth plate diamond mark (center 12AU7 spot) ..... for my Rogue Audio Cronus. Fantastic tubes making beautiful music. Life is good !