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 donĀ“t know when that is critical to the sound.
Please let me know your experience with your tubes and preamplifiers.
Sorry George, no experience with that specific tube that I can recall. Mostly compared the German tubes in that family. My favorites in the application I was using them in were the Siemens CCa's.

George - Unfortunately, yes, they are quite expensive and sometimes counterfitted or sold in less than desirable condition for large coin. If you go that route definitely go with a reputable resource. Expect to pay $75-150/tube (crazy!). Alternatively, in current production (or NOS if you like) I'd give a try to the Russian Rocket tube, I think they are 6H30 and are drop-in for most 6922 applications, but take care in which variety of that tube you use. I think BAT uses them in their gear. Worthy of a listen and much cheaper than NOS. YMMV and check on the application with your specific piece of gear.

I could be wrong but, I don't think the 6H30s can be used as direct replacements for the 6922s without some adjustment.