"N_Cook" wrote in message
...
What would cause the failure of one half of a 4 year old 12AX7 ? A very
careful owner.
One half tests out fine but for half using pins 1,2,3 cannot get any
zeroing
on the tester even setting current down to 0.5 mA or less and for any grid
voltage setting. Can't see any obvious internal weld failure.





12AX7's are a lot like human beings.


Everyone who's ever died...

amazingly was alive right before their demise.

Probably just a coincidence though G