I too am curious but I suspect it is just what robert8409 mentions. There is alot of heat generated with large tube power amps on top of the maintenence issues with the power tubes.
Any Problems with Conrad Johnson Premier 140?
I see a surprising number of Premier 140's available on the used market. Is this indicative of problems with this fairly recent offering from C-J? The amp sounds very interesting to me for running my Totem Mani-2's, but I don't need to court trouble. (Been down that road with ARC Classic 120's!)