well, something is or has gone wrong. About the 10-12 hour mark of listening to my 6LU8, I heard a pop sound from the right channel. The pop repeated and increased frequency to about one pop per second or so.
Switched speaker leads, it is definitely the right channel. I turned it off, let it rest a bit, and sure enough it comes back right away. Looking at the tubes while this is going on there is no sparking or arcing. I cannot see any hot spot onthe amp components, even the 5W cathode resistors are not hot!
So, any 'typical' source of popping? Bad caps? Power supply? any feedback on how to track down would be helpful. I am going to check all the wiring etc. , but I why would it take this ;ong to show itself? The amp had been in use for about an hour or so, having listened to it for at least that long several times now without issue.
Update: reviewed a few 'popping' searches on AK, decided likely a tube, so I swapped tubes and pop switched. Saw a small arc during a pop. Not looking forward to buying new pair of tubes.😣