Herbies tube damper tightness

How tight should Herbies tube dampers be?  I just tried to put an UltraSonic Rx damper on a 6h30 tube and it was so tight I thought it was going to crush the tube.  Is it normal for them to feel very tight during installation?


I have 3 integrated tube amps, a tube DAC, and a tube preamp, I've never found a need for tube dampers

If you bought them new, instructions should be there. Open them up so the rings have hardly any deflection.

@skids Thanks.  It never occurred to me that such simple devices would have instructions.  I did not buy them new, so I don't have the instructions and it doesn't look like they're available on their website.  Do you know what the instructions say about how tight they should be?  By your description, it sounds like it should be just slightly snug and not require very much force to install.

That's correct. Widen it so little to no deflection when installing. So hardly any tension on the tube. If you go too wide just squeeze them smaller.