There's no tube rolling for the 6H30 tubes. You can only use 6H30 tubes and only the Russians produce them. I think a couple of dealers sells an "NOS" version of this tube. I believe they were ones made in the '80s.
My friend had good experience changing to NOS tubes in the power regulating section. I believe it's an 5AR4 and a 6U6.
What tube dampers are you using? I believe ARC include the clear 3M tube dampers (look like a 1/8" thick spacer) with all their tubes, and they are supposed to stick to the tubes. Most of the legitimate aftermarket dampers are designed to withstand high temperature. But if the damper you are using is melting, it's probably not designed to be used on tubes. So, don't use it.
FrankC
My friend had good experience changing to NOS tubes in the power regulating section. I believe it's an 5AR4 and a 6U6.
What tube dampers are you using? I believe ARC include the clear 3M tube dampers (look like a 1/8" thick spacer) with all their tubes, and they are supposed to stick to the tubes. Most of the legitimate aftermarket dampers are designed to withstand high temperature. But if the damper you are using is melting, it's probably not designed to be used on tubes. So, don't use it.
FrankC