For drivers I like the Brimar 6sn7gty in V1 and a Tung-Sol 6sn7gtb in V2. I have heard the RCA red base 5692 is also very good. I haven't tried any different power tubes. I guess Svetlana 6L6 are supposed to be good. There is a Golden Tube mailing list that has a lot of dicussions about what tubes sound good and a lot of information about the SE-40. The address is firstname.lastname@example.org. You could go there and search the archives.
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