My personal favorites with the 11A were Sylvania (late 50's military issue) 6CF7s paired with Tung-Sol 5751s. Thought is was the perfect combination of detail, soundstaging and sweetness. RCAs in both postions were next in line, giving up a little in the detail department, but with good soundstaging (although not as deep as the Sylvania-TS combo), a little romantic sounding. I found GEs (in both positions) to be a little flat in terms of the soundstage, decent detail, least "tubey" sounding.