Tubes and their problems


I thought since I am currently having a few tube problems, and since i am not
that technically inclined, I would ask what are the typical warning signs and problems of our beloved tubes.
I will start off with the "popping" sound that I believe indicates either tube failure or impending failure ( perhaps someone can clarify why a tube does this?) What are the other various warning signs to look out for?
128x128daveyf

Showing 3 responses by czarivey

Microphonic tubes are usually ones that soon will blow.
You can tap amp chassis and if you hear tapping via speakers, your tube(s) are about to blow and you'll need to determine which ones by swapping between channels.
I would use sewing needle or similar that is able to go outside of contacting flaps and inside the socket and work on each one. Slight bending of tube terminals may also increase contact strength.
Tube that can't reach desirable bias may also be bad as well.
Every time when I replaced microphonic tube by new one the microphony of amp dissapeared.
Solid states usually don't have tube problems. The blown transistors happen far more rare than tubes and not too difficult to replace.