Component dampening

I have a nice quality tube preamp, but the casework, when tapped or thumped on either the front panel or lid will emit a slight ringing tone. I would like to eliminate this by lining the interior of the front panel and lid with some type of sound deadening substance. Any suggestions on what type(s) of material would help me realize my goal would be appreciated. Thanks...
3M makes some stuff, you can also get car audio padding for that purpose, like Dynamax (get Xtreme).

Try adhesive-back polymeric damping sheets. Used for vibration control, on pipes, cars (under the hood, for example).
Available probably at local (large) h/ware store. I got mine from McMaster-Carr.
Cheap and VERY effective in my system! Cut to size and use on front-plate, top-plate, sides, caps... (BUT BE CAREFUL NOT TO TOUCH EXPOSED PARTS OF CAPS WHEN YOU OPEN THE MACHINE).
Soundcoat.Email Frank At
I really try to keep my components dry. Dampening them is just not a good idea. DAMPING their vibrations, however, is
usually best done with a few pieces of sticky asphalt, and then isolating them with Neuance or Rollerblocks, etc.
Sorry to be the grammarian again....
By Asphalt, do you mean like asphalt shingles?

I actually prefer Ice and water shield, especially "Grace" brand.