recommendations for tube dampers???

I use the Pearl Tube Coolers on some of my small-signal tubes (as well as all of my power tubes), but I can tell you that though they seem to be effective at the job they're named for, they should not be looked upon as damping devices, and will in many cases add their own resonances to those of the tube itself. Sometimes they will shift a tube's inherent resonance in frequency, but will not absorb it, even with their woven synthetic jackets underneath the finned metal heat sink and the "rubber bands" around the exterior. Sometimes they seem to vibrate in sympathy with a particular resonant mode, and actually extend the vibration longer in time after the initial stimulus. Sometimes they do none of the above, and many times (in certain applications) none of this will seem to make an audible difference anyway. But with critical tubes in hi-gain blocks, another type of device is probably the way to go. BTW, I have found that I have no real way of knowing whether or not the Tube Coolers are actually extending the life of my tubes, but they do seem capable of rapidly acquiring and dissipating a high degree (ha!) of heat. The only other downside I have found is on the power tubes only, the very high temperatures involved will bake the "rubber bands" into a hardened state, rendering them useless when you have to change tubesets, so stocking up in advance is a good idea (try Michael Percy Audio).

"...a little bit of microphony can be a good thing, and is probably one of the reasons we all like tubes"

Re-reading my post from eight years ago in light of the above-referenced comment, I feel compelled to say that for precisely that reason, among others, I don't use tubes anymore (for hifi that is -- guitar amps, always). After several years I grew tired of usually being able to "hear the tubes" to some degree when listening to recorded music, especially at realistic volumes. And I found that tubes are no longer necessary (in addition to putting up with their waste heat, replacement costs, inconvenient and occasionally catastrophic failures, and higher noise) in order to get lively, flowing, open, naturally consonant sound, including musically convincing bass. On top of its inherent advantages over tubes, good solid-state achieved parity in those regards a while ago IMO.

I think you're right BW, I should've put an exclamation point or two after the phrase "eight years ago"!! But I got posted-out on audio a while back and have mostly sworn it off since. However it's nice to get a welcome wagon rather than flamed for daring to diss the holy tube (which I'll always love even if I don't use 'em anymore), so thanks dude :-)

Hi Kats, not saying that tubes are never worth it or that SS sounds tube-like, just that to my ear the flaws I often perceived which made much SS a musical compromise, seem to have been proven largely solvable by this point. (And I know one leading long-time manufacturer of both tube and SS amps feels this is the case.) So IMO abiding tube disadvantages isn't imperative to get sound that's not constipated and synthetic sounding.