Microphonic from Vacuum Tubes?

HI,  I have a question regarding microphonic from vacuum tube.  I have a Cary SLP-05, and I've changed the output gain tubes to some NOS RCA, and also recently purchased a pair of Linlai for the balanced buffer stage.

I now occasionally hear a loud pop in the music.   It doesn't happen very often, but when it does, it is quite loud.   This happens when I am streaming digital music, so it can't be those occasional pops you hear from vinyl.  

Can someone tell me if this loud pop possibly caused by microphonic in my tubes?  if so, how do I track down which tubes?   My guess there is no easy way but change one tube at a a time, which can be extremely time consuming.   Also I don't own a tube tester.  I wonder that would help tracking it down.

Also I read something about vacuum tube damper rings,  would that help calming down possible microphonic?

I still  consider myself a newbie in tubes,  so any hep will be appreciated.  Thanks very much.


Tube(s) getting too hot….all you have to do is wait for pop then generously spray all the tubes with water. The bad tube(s) will obviously be obscured by a cloud of vapor.


@sevestan , you are joking, right?

When capacitors go bad.  Could be anywhere as the noise also travels back to the PS if common to both channels.  Hard to troubleshoot sorry.

If tubes are arcing, rap on them with a screwdriver.  Try to reproduce it


If you suspect capacitors in the power supply, you can at least do a visual inspection.  Bad caps often leak when they go bad, or even more commonly, they bulge.  The bulge is most evident at the ends of the capacitor, particularly the top.  Compare the capacitors to each other and if one has a top that looks like it is sticking up, it may be the bad one.