At 365V across the tube, that bias point is 28W or 77% of max rating of 36W. This is actually hotter than many people run a 300B and given the cost of these, most people don't push them to their limits, especially modern china copies. If you look at the WE datasheet, they show most of the recommended operating points for this tube run at 350V at 50-60ma. They don't even show anything over 80ma. I've also read most of the modern "knock offs" are closer to a 30W tube max so this point would then be over 95% of max. Clearly if you feel brave, you can push it harder if you need to extra power, I don't :)
I am brave, but not stupid 🙂 Thanks for the answer/explanation.
I did finish my 300B amp yesterday, but gets a "file to big" message when I attempt to upload pictures.
It was a very cool project, thank you for the effort you put into this tube amp stuff.
BR. Henrik.
At 365V across the tube, that bias point is 28W or 77% of max rating of 36W. This is actually hotter than many people run a 300B and given the cost of these, most people don't push them to their limits, especially modern china copies. If you look at the WE datasheet, they show most of the recommended operating points for this tube run at 350V at 50-60ma. They don't even show anything over 80ma. I've also read most of the modern "knock offs" are closer to a 30W tube max so this point would then be over 95% of max. Clearly if you feel brave, you can push it harder if you need to extra power, I don't :)