How to isolate turntable from footstep shake or vibration

FWIW and noting that this thread has taken a side route, here are just two documented sources for tube microphonics;

-Proceedings of the Institute of Radio Engineers, Volume 17, Number 9 September, 1929, MICROPHONIC IMPROVEMENT IN VACUUM TUBES  IRE-1929-09.pdf (worldradiohistory.com).

-Getting the most out of VACUUM TUBES by Robert B. Tomer, 1960,  Getting the Most out of Vacuum Tubes (worldradiohistory.com)

This site has THE HISTORY  RADIO and BROADCAST HISTORY library with thousands of books and magazines (worldradiohistory.com) and this site is an amazing resource.  Its takes some time to figure out how to use the many search features, but once you do, it can answer many of the  questions or technically guide conversations associated with this  technology that is proving to still be relevant as it enters its 2nd century.

Who’s jumping on the floor when you guys listening to your records? 

I have been using a Sota since 1981 and have had it on everything you can think of playing through ESLs. I have not found anything to be as important as using a dust cover during play attenuating airborne vibration by as much as 20 dB (not sure how accurate the meter was). Like protective earmuffs for your cartridge. And, everyone thinks this is poison (except Mark Dohmann). I guess like guitar amps everyone likes listening to distortion? With subtle differences I guess people prefer sticking with mythology than really listening? Boggles the mind.

@mijostyn  I had a dust cover for my Sota as well. When I added the custom stand and platform the improvement was instantly audible- it was not subtle, and it was also measurable- the latter being done by playing a test tone and cranking up the volume- you could easily see on the oscilloscope how much less 'disturbed' the waveform was prior to the volume control (we had the 'scope on the tape outputs).


We had a modified Empire 208 (which was the platform for what later became our model 208; at the time the 'mods' where a damped platter and an SME5 mounted to it). As you turned up the volume the Empire 'fell apart' sonically compared to the Sota. But when either one was placed on the stand with platform neither one fell apart- at that point the Empire sounded better since it was so much more speed stable (the early Cosmos machines had a stability problem that was later fixed) and had a more massive platter that had more damping. Both machines used the same platter pad as I mentioned earlier and both used the same arm and cartridge.


It was thus very easy to show that the anti-vibration measures were having a profound effect on the system when the volume was cranked up.

Tube guitar amps provide a range of tone from very clean to smooth, controlled distortion. Microphonic tubes become very obvious in a guitar amp, yet rarely occur. Read a review of any tube guitar amp and you can learn something about them.

Wolf, as you probably know better than I, if you actually play guitar, guitar amps are distortion generating machines. The distortion is intentional. This is one reason why overstressed tubes are preferred by the cognoscenti in guitar amplification, unless you disagree. One form that that distortion takes is due to the microphonics of the tubes adding to the other distortion generating characteristics of the circuit. Don’t you think? Speaking for myself, when I hear a really prominent electronic guitar solo, I think I can hear components of the distortion that are due to tube microphonics or are very characteristic of distortion caused by microphonics. I just don’t think there is much effort to avoid microphonics from guitar amplifiers in general. 
Furthermore, I and others have been saying all along that microphonics are more or less of a problem with certain tube types and with tubes used in circuit in different ways. Hi gain tubes that have a large glass envelope tend to have the most problems with microphonics. Small nine pin miniature tubes like mijostyn‘s 6922s are perhaps a bit less prone to microphonics, but Atma-sphere seems to disagree. Tubes used as cathode followers, i.e., to convert voltage into current and add no gain are less prone to microphonics. If one cannot hear a certain kind of distortion or noise in one’s audio system, that does not mean it is totally absent. It just means you can’t hear it. Which often is good enough.