Power Tubes for Twin Reverb

[Tonegeek]

Tung Sol 5881's can only take 400v on the plate. I can't seem to find specs on the Sovtek 5881 at the moment. Anyway I hesitate to use 5881's in amps running SS rectifiers for that reason. I tried some old Tung Sol 5881's in my Dumble clone at 450 volts on the plate and they sounded fabulous but one of them smoked after 10 minutes. My bias was set at about 70% dissapation so not over the top. Being militarized mean they are constructed for toughness, but you still have to respect the ratings. Anyone else tried running these beyond their ratings and what is the outcome?

[billyz]

I have measured quite a few old Bassmans with over 450 volts on the plate all running original Tungsol 5881's. 5f series and 6g6 series. I also had a couple of tweed twins running 5881's at well over 450vdc on the plates , these amps are over 40 years old and I am sure the tubes were original.
Fender was notorious for running the tubes past the the design center specification though.

The New reissue Tungsols are not the same tube. They are not of the same quality so the design center max may be more critical.

[Tonegeek]

I have measured quite a few old Bassmans with over 450 volts on the plate all running original Tungsol 5881's. 5f series and 6g6 series. I also had a couple of tweed twins running 5881's at well over 450vdc on the plates , these amps are over 40 years old and I am sure the tubes were original.
Fender was notorious for running the tubes past the the design center specification though.

The New reissue Tungsols are not the same tube. They are not of the same quality so the design center max may be more critical.

I think the tubes I tried came out of an old Bassman, at least I was told that they did. I sure wish I could get that sound again but hesitate to use the newer ones because as you say they are not the same quality. The 6L6's I have tried did not sound as good as the Tung Sol 5881's did or I would use them.