These days ARC only puts dampening rings on small tubes. Not big power tubes.
This does not take away from the argument that tubes can be microphonic. I suspect the large power tubes may run so hot, that they cannot use those dampeners.
Tube microphonics
Hello. I am using Audio Research Ref 750 mono blocks and they in front of my speakers but off to the sides. Someone told me on another site that if I move the amps beside the speakers and not in front of them , my system will improve immensely. It will reduce tube microphonics. What are your opinions of this and I just want to say that I’m very new to tube amps so this is something I never heard of before. Thank you all.