2. tech-talk
  3. 123279-2280

Vibration Control for Lightweight Tube Components

I'm looking for suggestions to isolate a lightweight tube preamp from vibration and resonance. Not acoustic vibration, but physical vibration from the stereo rack. When I touch the shelf the preamp sits upon, the sound can be heard thru the speakers.

I am using a heavy furniture grade stereo rack for my components, all using Herbie's Tenderfeet for isolation, including my TT. The preamp only weighs 7 lbs. and has Herbie's tube dampers applied, but needs to be decoupled from the heavy wood shelf. I've tried the Tenderfeet and Vibrapods under the preamp, but neither provided isolation from vibration.

So, what are owners of lightweight tube preamps and amps using for vibration control? (there is a limited amount of space between the shelves).
128x128lowrider57
bdp24's avatar
bdp24
9,703 posts
 
Spencer---Actually, in my post way up above I mentioned placing a trio of roller bearings (the generic term for what Symposium calls their Roller Block) between the pre-amp and Baltic Birch plywood shelf I suggested. I didn’t name a specific brand (such as Symposium) because there are a few people making them.
geoffkait's avatar
geoffkait
23,365 posts
 
Since there are six count ’em directions of motion for which isolation would need to be applied and since springs isolate quite well in the vertical direction and isolate somewhat less well in two of the rotational directions and, practically speaking, not at all in the twist rotational direction or in the horizontal plane, a comprehensive solution would be mechanical springs plus roller bearings, which are rather good at isolating in the twist direction and the other two rotational directions as well as the horizontal plane, but hardly at all in the vertical direction. Voila!
lowrider57's avatar
lowrider57 OP
5,411 posts
 
Mass loading on top of a component is advised, if possible for its dampening and absorption properties. Something I have found most effective for this, I no longer know where to source. They were paperweights, leather bags filled with lead shot, used to hold down large architectural roll size drawings. Perhaps diving ballast bags would do the trick and be most cost effective.
@r_f_sayles, I plan on mass loading if I can find some weights that are only 2" wide. It made a significant improvement in sonics to my previous preamp. I’ve been looking thru my house and workshop for a DIY solution.
Maybe some calibration weights for a triple-beam scale. Too bad I got rid of my scale years ago, LOL.
mesch
3,463 posts
 
Yes, I mass loaded my amp, pre, disc player. I used barbell weights with 1/8” cork bottoms. I didn’t have your spatial constraint however. I am sure you can find something at a hardware/farm store that would provide an inexpensive solution. Happy hunting!

geoffkait's avatar
geoffkait
23,365 posts
 
Gee, funny no one mentioned Herbies tube dampers for all tubes, rectifiers, 6SN7s, 12AX7s, you name it. Would you believe two dampers per output tube and rectifier often sounds better than one? One on the glass, the other on the base. Yeah, I know, that's more than the cost of your tubes just for the dampers.  And of course the transformer needs to be wrapped with mu metal (and physically damped).  The tubes are sitting right in from of that big honking magnetic field.  Hel-looo! And now sis the time for the cork, isolating the circuit boards. 
More to discover