Pin 9 on 6n6P, 6H30, etc

[dsavitsk]

What is the best thing to do with pin 9 on these tubes? Should it be grounded, left floating?

 

[Mikael Abdellah]

I usually tie it to ground. Escpecially if Im using both sides of the tube. It can never hurt to shield something.

 

[Beelzebub]

John Broskie recommends a capacitor to ground in his Aikido circuit, although this has as much to do with facilitating valve choice on his circuit board as anything (a capacitor will provide an AC path to ground). Why not try both and see what the results are?
Jim

 

[hagtech]

Best to tie pin 9 to ground or something. Else you allow coupling between the two plates.

jh