Tubes and microphonics

I want to know when microphonics affect the sound.
I have a Sonic Frontiers Line 2SE Preamplifier. I tried many tubes like Valvo, Siemens, Reflector 6H23NEB.
Recently I bought two matched pair of Amperex 6922PQ White Label Made in USA. I think that the Amperex are better than the others, but I could see that they are less silent.
When I knock the cover of the preamplifier I can hear the knock clearly in the speakers. That not happen with the others tubes. The 6H23NEB are the most silents.
I think that Amperex have more gain than the others. But I don´t know when that is critical to the sound.
Please let me know your experience with your tubes and preamplifiers.
Thanks,
Pablo