Prefered 300B tubes for Canary Amplifiers

I think the WE spec was "up to" 40K. Like Charles mentioned, it depends on how hard they are ran (voltage and current).

I have 2 300b SET's, that run the tubes in the low 20's watt/dis. I have a PP 300b that actually runs about the same maybe a little less.

Gary,
I know, 40K hours is hard to grasp.As Brf pointed out however this tube was designed for very long and trouble free use fot telephone line service. This was meant to be from the outset an ultra low maintenance service tube. What is critical is how meticulously the various current 300b tubes are made.Suppositly this is a design objective by the Japanese engineers assigned to the Takatsuki project.The tubes are too recently developed to know yet their longevity. I can only attest to superior sound at this stage.
Regards,

Charles1dad, what kind of speakers do you have for the 300B amp?

Orpheus10,
You can click my system and see pictures and description of the Coincident Total Eclipse II.
Regards,