Expanding questions about tubes in a preamp

As others have shared, there are types of noise that are intrinsic to the component and the tube itself. As geoff points out all tubes have some degree of microphonics and the gain of the component in which the tubes are used has a huge effect on this phenomenon. Placement or isolation of a component also can have positive results. I agree with ieales that damping, isolation or relocation of the component are where you should start. Hiss is usually a component issue. I do not like dampeners for numerous reasons not least of which is mentioned by Ralph at Atmasphere. 

Dont listen to wolf he is dead wrong on this one.  

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. 

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.