Tube dampers screw up the thermal heat transfer of the tube and should not be used!
Tubes, to damp or not to damp?
I’ve not had much luck with dampening devices when it comes to tubes. For myself, it seems to strangle the life out of the music. Tubes just seem to have more life without them. Maybe I’m using the wrong ones? I purchased a few from Audio Research the black rubber type. Any thoughts on this subject would be interesting to hear.