How to isolate turntable from footstep shake or vibration

@atmasphere,  I don't believe in miracles. ARC put tube "prophylactics" (damping rings?) on the tubes. I have no idea if this cuts "microphonics" 
@lewm , I'm not talking about hitting the tubes with a baseball bat, just light tapping. Yes the PH3-SE is a hybrid design. I think it uses a FET front end.  At some point you have to rely on experience. (and people you trust)

The next question is if tubes are microphonic how much energy or input does it take to make them sing and how does this affect sound quality. Will putting a tube phono stage on an isolation base change the degree or level of microphonics and can this be quantified. What about solid state. My preamp is digital. When I get home I'll put a wooden block on it and bang the block with a hammer to see what happens. That is way more energy transferred to the chassis than anything being transmitted by air or through it's feet. Once turntable is set up I'll do the same to the phono stage, the Oppo and the Apple mini to see what kind of noise I can generate. Next, I'll put my cell phone's volume up all the way and put it on speaker phone. Then I'll put the phone directly on each piece of equipment and I'll run a slow frequency sweep through the phone (what ever frequencies the phone will transmit). With the phone in direct contact with each unit that should transfer more energy to the unit than any system can. The the volume on my system turned all the way up we will see if we can hear anything!

ARC put tube "prophylactics" (damping rings?) on the tubes. I have no idea if this cuts "microphonics"

:) of course it does! Warren Gehl of ARC came up with that material (he also designed the Sumiko Analog Survival Kit) and it is one of the best materials I've seen for controlling microphonics in low signal tubes.

The old MFA luminescence preamplifier was one of the best sounding single-ended preamplifiers ever designed, and it used 6SN7, 6EM7,and 6SL7 tubes, all of which are octal-based triodes with large glass envelopes. I owned a luminescence that would sing if I turned the music up too loud and it was very obvious what was going on. I was able to tame them after a while. And with dampers. Sadly for those who love them as one of the best sounding small signal triodes ever built, the 6SN7 is one of the culprits for being especially microphonic. In fact, the best and most rare ones are often the most prone to microphonics. It’s a problem you live with, if you love the tube and how it sounds. Another thing to consider is that the level of microphonics for a given tube in a given circuit often is related to the signal gain developed inside the tube. I am beginning to suspect that in your AR preamplifier the 6922 is used as a cathode follower. Cathode followers develop no gain, and that may be why you are having no problem with microphonics even when tapping on the tube. Just a guess.

@lewm , I am very simple minded Lou.Insted of buying very elaborate isolation plateforms I would prefer buying equipment that is not affected by the minimal amount of vibration present in a sturdy cabinet. I find it interesting that I see systems with elaborate platforms for the electronics and a turntable that sits on simple feet. I get a Sota mostly because it has a dynamite suspension and is impervious to anything happening around it. The same can be said of several other turntables but not the majority and it is very hard trying to get the message through that heavy plinths do not qualify as a suspension. Turntables are different because it is their job to "measure" vibration. No other component does this and is near as sensitive in this regard. Maybe some tube equipment is susceptible. You and Ralph would be far more knowledgeable on that subject than I am. I only have one tubed unit. But, I have a hard time believing and piece of electronic equipment would be as sensitive as a turntable.  

My turntable levitates : https://solidairaudio.com/product-category/special-offers/
It works very well.