Fixed BIAS in a tube microphone.

[vmanj]

strange. Does your capsule have a membrane on the front and back? The 'backplane' is the metal center, it is not the membrane on the back, if you have a dual sided capsule. You are just swapping the connections of the bias and grid.


Just for long term durability. You can use a trimmer

I have a one-way capsule.
Everything works fine in the previous scheme.
I also tried changing the capsule connection (front and rear (ground).

Changing the capacitor value from 100 to 10000 pF, unfortunately this did not change anything ..
This is really weird ..