A lot has been said about microphonics of the quickie and its 3S4 tubes. Mine came with Sylvania 3S4s and they have proven to be fairly microphonic (OK, very much so, though much less annoyingly than some 12AU7s in another preamp). They ring like a bell for 3-5 seconds when I touch the amp in any way (or fuss with the far end of some rigid interconnects). Even moving my hand toward the switches or knob starts the ringing. Once it dies down, it seemed to play quite well.
So today I did a little experiment that others may be interested in (though most here probably have much more knowledge than I do). I wrapped some fat rubber bands around the tubes (after noticing that the tubes remain cool even after several hours of use) to mimic some higher quality tube dampers I have for larger tubes. See the photo attachment.
(http://picasaweb.google.com/103078014592468973736/Bottlehead#slideshow/5537771006395854690)
In short, even with this low-tech approach the microphonics have been cut at least in half. If I do a L/R comparison, the side with the rubber bands is highly improved. And...there is definitely a noticeable improvement in the playback quality with the bands on. I assume there was some residual ringing during playback due to the fact that my speakers aren't too far from the quickie (about 3ft away, and using a 100wpc Marsh A200 amp and Vandersteen 1C speakers). I suspect this ringing muddied certain frequencies when they played back, as now I get quite clear and highly separated playback. To me it is very noticeable.
I will play around with playback using different dampening materials with the tubes and report back as I do. I hope others will report their experiences too.
