7A5 is a good driver for the 300B ?

[Vinylsavor]

Hi!

And a 6HV5 do not can driver a 300B ?

It could, but you would need high plate voltage and a step down interstage transformer, otherwise the drive impedance would be too high and the gain also way too high.

I used the 6HS5 to drive a 211 through a 4.5:1 step down:

VinylSavor: Making of a 211 Amplifier, Part 1: Planning

Best regards

Thomas

 

[tcqanh]

Tom

Thanks for the information, but I prefer pentodes for driver the 300B.
About the triode tubes, I prefer the 6N6P and 6BL7..

Aldovan

You can regard some penthodes with high Gm, high gain like 6E5P, 6J52P, E810F, D3a or C3g...

Playing role a power amp Vanode is 180-200V, Vk above 2.5-3V with interstage transformer(IT), you can have enough swing voltage for power tube.

Try to use IT one time and feel the differences... 🙂