Implementation of G2 and G3 in ef86 in U67

[SparkleBear]

Can anyone discuss the g2 and g3 implementation of ef86 in u67 circuit? G1 is obviously the signal from the transducer. G2 is tied to plate anode and g3 is tied to cathode. I’ve only really worked with triodes in my mic circuits in the past.

Thanks for sharing the wisdom

 

[Khron]

https://www.enjoythemusic.com/magazine/sound_practices/2/triode_pentode.htm
http://www.audiodesignguide.com/New2A3/ETF06TS.pdf

 

[SparkleBear]

http://www.audiodesignguide.com/New2A3/ETF06TS.pdf

Thanks so much for the reply friend! It was a fascinating read... exactly the information i wanted to know.

 

[mhelin]

There is also another way to triode strap a pentode not mentioned in the linked document. That is to use the screen grid as plate and not connect (N.C.) the plate at all like on GT/ST66/69 mics with 6205 subminiature pentode (schematics can be found on this post):
https://groupdiy.com/threads/gt66-tube-mic-voltage-requirements.81830/#post-1056007