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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
geoffkait's avatar
geoffkait
23,365 posts
 
I have one word for you, mass on spring.  Almost all effective vibration isolation solutions employ this simple technique.  
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cleeds
5,950 posts
 
It sounds like a microphonic tube. No preamp should be so sensitive to vibration that merely touching its shelf generates sound through the speakers.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
It's not the tubes. It's a new Atma-sphere pre, new tubes, and I have also rolled in some other tubes. IMO, the unit needs to absorb vibration or be decoupled from the shelf.

My previous Rogue preamp, also with exposed tubes, experienced the same problem. (it weighed 30 lbs.). I used Herbies as footers and also mass loaded the top to stop the vibration.
It's similar to a footfall issue.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
@geoffkait , what do you mean by mass on spring?
geoffkait's avatar
geoffkait
23,365 posts
 
@geoffkait , what do you mean by mass on spring?

Any any isolation device that employs airsprings, mechanical springs, tennis balls, bungee cords, etc. operates as a low pass mechanical filter for vibrations, where the component represents the mass.  The springs are selected in terms of how springy they need to be according to how much mass is to be isolated. So for very heavy components the springs would have to be very stiff, otherwise they would compress too much under load.

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