Heat is the enemy of tubes- they ought to be kept clean of dust and fingerprints for the longest life. 6DJ8s and 6922s are capable of running a fair amount of current and so can get quite hot.
Tube handling/designations
I recently purchased a BAT VK-30.It came with 6922 Teslas installed as well as the original Sovteks.I would like to try some different tubes to see how they affect the sound.My first question is do you need to wear gloves so as not to get oil off your hands on the tubes like halide lights?My next question is are 6922's the only tube that will work or are there others?I ask this because in some ads for tubes I see a slash followed by EE????.Also,what does NOS mean and why are they supposed to be better?