Tube gear can be microphonic and more sensitive to vibration but I just (now) did a test on my ARC LS16 tube preamp and CJ Premier 11a tube amp.
I switched the preamp to an input that didn't have a source component connected to it, turned the volume control almost completely open 3 O'clock position. I then tapped my knuckles around the LS16 tube preamp then on each side of the Premier 11a tube amp and the top of the amp near the tubes.
No "boiiing" sounds or other indications of microphonics AT ALL. No sounds coming from the speakers, i.e. can't hear the sound of my knuckles tapping on the gear thru the speakers.
I switched the preamp to an input that didn't have a source component connected to it, turned the volume control almost completely open 3 O'clock position. I then tapped my knuckles around the LS16 tube preamp then on each side of the Premier 11a tube amp and the top of the amp near the tubes.
No "boiiing" sounds or other indications of microphonics AT ALL. No sounds coming from the speakers, i.e. can't hear the sound of my knuckles tapping on the gear thru the speakers.