Do tube dampers really work?

Having just been told in no uncertain terms by several other Audiogoners (in another recent thread) that tube microphonics have been a non-issue since the 1940's, I hardly dare to raise my head here. But I can't resist. Lessee, you've a bunch of hairthin wire wrapped round and round some rather flimsy posts sticking up into free space, all wrapped up in a glass bottle. And this whole thing is guaranteed to be absolutely 100% impervious to vibration of any kind (not 99.9%, but 100%, mind you!). I ain't buying it, even if it's free.

If you really want to know for certain, take the cover off your tube preamp, turn on your system, turn the volume up, and twack the tubes nice and hard with your fingernail. Do you hear anything through your speakers? That will be pretty indicative of whether tube dampers will help or not. Disclaimer: DON'T TOUCH THE ELECTRICS inside the preamp!

If you try it, let us know what you find.

Yes, I know that tapping tubes is a much more severe G load than typical air loads can impart. However, it is significantly closer in magnitude to conceivable chassis-borne vibrations. (Have you ever put your hand on your preamp's chassis while loud music is playing?) Still higher, I grant you, but this is really a matter of simple physics. In fact, one of the simplest of all physical equations. Namely, that a specific force will cause an acceleration (and yes, a subsequent ringing) that is exactly proportional to the magnitude of that force. Moreover, a simple fingernail tap is about as close to a step function as you can get in a no-cost test, which has all kinds of benefits in analyzing how a tube (or any other physical/electrical system) reacts to transient perturbations (which is about as close to a general definition of a musical signal as you can get). So yes, the test I proposed is more severe than the tubes are going to see in normal service, but it is nevertheless a totally valid way of easily demonstrating that tubes are indeed sensitive to vibration. Anyone who denies this as an absolute impossibility has their head in the sand. (And I'm being polite here.) Go reread Hee's post above and then tell me that this problem doesn't exist.

Well, ARC does it on all their stuff, one of the reasons I like them. As for why others don't, the cynic in me wants to say that they probably don't want to admit that it's a problem. There's a psychological issue with admitting to yourself that tubes are sensitive to vibration, makes them seem somehow less "perfect" than they were before, and also makes the customers start asking difficult questions, like "why aren't you doing more to isolate the tubes from vibrations, if vibrations clearly cause a performance degradation?" Best not to go there. Witness the several responses above stating categorically that microphony cannot possibly exist unless the tubes are obviously defective. To some, a problem ignored ceases to be a problem. I just wish it worked for me:).