I'm sorry to here of you lose Springbok10.(belated)Hope all has been well since.
I'll have to stay in touch with this issue as I poses newly updated Atma-Sphere MA-1 Silvers that Ralph and his fine crew just updated. I feel the new caps are finally burned in, and could not be a happier camper than with Ralph's OTL's. Simply brilliant! But I'm running them through... Coincident PREt's with the Accuton's. Again, Israel Blume and his speaker designs, have just brought the whole thing together. At this point, no problems and no need to expect any... the music and performance is lovely.
I too am unwilling to part from my Atma-Sphere's, I'm OTL hooked.
Never had one of Andy's choice Sylvania 6SN7's go yet either, but have had two 6AS7G/6N13S Svetlana power tubes go, in over seven years of faithful service, but when they did, it was absolutely frightening! Yet, no damage.
Happy Listening! ;^)>