AS with $5 vacuum tubes, $150 audio vacuum tubes sometimes fail at an early
age.........One culls them out and often very old tubes just keep on going
fine. 12AX7's have become "fools gold" in this inflated acoustic
psycho-babble golden ear but tin brain market...........

"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.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
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