THE GREAT MULLARD MAGIC BLOG — Mullard Magic Toob-Tickler

From this quaint photograph from 1928, you will see that valve damping to reduce microphonics is nothing new.   In this example, a pioneering radio enthusiast decided to apply his damping using Plasticine.  As we all know from our childhood, Plasticine, is the proprietary name for a rubbery mixture formed when  calcium stearate, petroleum jelly, palmitic and stearic acids and a dash of colour  and mixed together with the application of heat.  It has all sorts of uses from making Wallace's "wrong trousers" and many childhood models, some rude(!) as well as it seems of damping microphonics and protecting the glass...