Expanding questions about tubes in a preamp

Hi,
wolf_garcia,
how do you explain same tube being microphonic on gain stage and not on the driver stage?  Same pre no tricks, no dampers used. Same quiet scenario in the more sensitive phono stage. It was a CCa 1962 pair brand new. Did i throw away the tube? No, used it, enjoyed it and after 2000hrs sold it to a new happy owner and the tube is running quiet and strong as new. Why i sold it? I am done with NOS tubes, just kept 60 of them after being struck with NOSphilia and having owned 552, a small fortune. That was an example and i have similar findings with other NOS tubes having  microphonic tendencies in the phono stage and being quiet in the line stage. Dampers do work in cases and it is not paranoia, but just a way to solve an issue. Just tossing a tube does not help.

ieales,
"A with tube damper testing is it is impossible to install / adjust them without moving the tube and refreshing contacts"
you can surely adjust the position of the damper on the glass if you use something that can roll on the glass while a tube is working (with gloves of course).
The way i put it is you may or not hear a differene but is far from anecdotal.
I agree with you that any chassis damping will have positive results for resonance control especially in areas like focus and bass quality.

Skeptics say anecdotal, audiophiles say empirical. 

geoffkait :
I enjoy your post very much and over the past couple of years have learned a lot from them.  But, you have a nasty demeanor.  Why is it acceptable to verbally assault others?

Hope I'm not putting words in @mulveling mouth--get a tube preamp that uses a better tube. I've never liked preamps with 12AX7s--the timbre seems off and dynamics seem non-linear. Hard to be sure, though, as it is the whole system being listened to, not just the tube type. In the preamp alone, there is the circuit, its parts quality, its layout, its build quality, and its output impedance match (or not) to the amplifier input. Add the source, amplifier, loudspeakers, cables, and the room and who knows? Even with something like the BHK preamp which uses either tube, there is still the possibility for optimization for one or the other.

Gents, how the hell does adding damping rings change the sound of a tube. Nonsense!

Answer: by reducing microphonics. The effect is easily measured and heard.

But using a low microphonics tube is more effective yet. Installing dampers on them has the most effect.