Expanding questions about tubes in a preamp


Hello to all...

Started with a (helpful) discussion titled "How to select tubes for a line level preamp"... Expanding questions that have generated from that...

Have learned that hum/noise from tubes is a major consideration - now trying to figure cheap ways to address quieting the 12AX7s and the EF86s.

Would like to try "banding" the tubes with rubber ring washers - one?two?three per tube?

Where should the rings be on the tube: Top? Mid? Bot?

Can you over dampen a tube?

Knowledgeable tube users/ Masters input/suggestions please...

insearchofprat
I'm absolutely right, but I do get that the insecure among us do get testy when somebody pokes holes in their silly paranoia driven tweaks...don't be sad "auddie"...again, dump audibly microphonic tubes...you won't regret it.
Which post indicates insecurity? I have sold vacuum tubes on both a retail and wholesale basis for over 20 years so I think it fair to assume that I test more tubes in a day than you do in a year or perhaps over your entire life. Please tell me your vacuum tube qualifications other than using tube gear, albeit relatively pedestrian gear. You tend to believe that if you dont hear something that it doesnt exist. 
If you’re selling tubes you have a commercial stake in this nonsense so it’s no wonder you’re a bit testy (accidental pun) as helping people be worried about non-issues is clearly part of your business model...ethics be damned! If I don’t hear something it doesn’t matter to me. Period. I’ve owned piles of not so "pedestrian" (and you’re also a tube amp elitist? yeah man...insecurities galore dude) tube amps since the mid 60s, microphonic tubes are so rare as to be irrelevant, and if they display an audible bit of microphony they’re gone (in my career as a professional musician I can’t afford risking a bad tube)...I don’t need to test tubes as I can hear them, and that’s all the qualification I need.
I dont see how anyone could ascribe a commercial interest in this conversation. Actually the number of microphonic tubes one encounters is directly dependent on the number of tubes used over the years and also the sensitivity of the application. As sensitivity increases so does the percentage of microphonic tubes you will encounter. Put a fork in me....this is hopeless.