“EuroDamper” Tube Damper Rings Extra Large for 6550, KT66, KT88, 300B and 2A3 Power Tubes. One Pair.

These are great for dampening tube rattle. They fit my new combo amp perfect as they came w the larger tubes

Had them for only a couple days they smelled very first time Then I heard one snap I realized that the tubes got too hot made them brittle I would not use them for a class a amp.

I had difficulty with Arcturus 127 vacuum tubes in my preamplifier picking up transformer humthrough microphonic action. I switched the cathode heaters to filtered DC and I have aggressively filtered B+. When I put my hand on the tubes the hum goes away. These collars improved it but I can still hears some hum if I put my ear close to a speaker, but hot from a normal seated listening distance. They help.

Liked the tube damp

It’s beautiful and so comfortable