Most O-rings are Buna-N, also called nitrile rubber. These won't take the heat. Viton fluoroelastomer is much better at the heat, up to 400°F, and silicone to 450°F.
I bought a used TAD-60 tube amp that came with Herbie's tube dampers. They appear to be very good quality, but make no audio difference on this rig. The designer of the amp, Paul Grzybek, suggested that if a fingernail tap on the tube creates a sound from the system, try dampers--this unit doesn't.
I bought a used TAD-60 tube amp that came with Herbie's tube dampers. They appear to be very good quality, but make no audio difference on this rig. The designer of the amp, Paul Grzybek, suggested that if a fingernail tap on the tube creates a sound from the system, try dampers--this unit doesn't.