You did not mention what the amplifier is.
A few years ago I owned a prominent name brand amplifier that used 6922 tubes and after destroying several NOS Telefunkens and Amperex tubes, discovered the bias was in error by 300%.
Might check yours. Other option already mentioned that these could be faulty to begin with. Either way, something is beyond the norm.
A few years ago I owned a prominent name brand amplifier that used 6922 tubes and after destroying several NOS Telefunkens and Amperex tubes, discovered the bias was in error by 300%.
Might check yours. Other option already mentioned that these could be faulty to begin with. Either way, something is beyond the norm.