Vibration Control for Lightweight Tube Components

Lowrider57 wrote,

"@geoffkait, I thought they might be "spongy" like the 1/2 tennis ball concept."

-- tennis balls or 1/2 tennis balls don’t have the right spring action to act like a real spring either. You actually need to match the spring rate of the springs to the mass of the component. I’m not saying tennis balls or bicycle inner tubes or gooey type devices won’t do anything, I’m just saying they’re just not as effective as real isolation devices, like my springs. While gooey or rubbery type materials like these or say Sorbothane might seem like good materials, even perfect materials for audio applications, they seem like such a good idea, right? But they are a pig in a poke. You will do much better with mass on spring plus very hard materials to support the iso device and to support the component on the iso stand, generally speaking. It has been 20 years since the Vibraplane iso stand blew into town. That changed everything.

"The ad goes on to state...
IsoNode feet are specially engineered from a unique polymer that rejects a wide range of vibration trying to enter from underneath the component. The highly compliant IsoNode acts as both a liquid and a solid for superior vibration control. Vibration and resonance that could interfere with the performance of sensitive electronic circuitry are converted instead to extremely minute amounts of heat and harmlessly released."

-- They are apparently viscoelastic in nature and act together with the load as constrained layer dampers. I’m not saying they won’t work to some degree but to deal with very low frequency vibration you need real isolation, as opposed to "vibration control." You can have both, which is why they suggest they can be used UNDER a real iso stand. At least that’s what they say. How you should support a real (mass on spring) iso stand is another issue unto itself as well as how you should mount the component on the iso stand.

"BTW, I googled "mass on spring" and I see that the spring has a non-negligible mass."

-- A spring (steel spring, air bladder or bicycle inner tube or air spring) would usually be what, 1/100 the mass of the component being isolated? Where I come from that’s negligible. My springs are the lightest in the business, coming in at around 1/200 the mass of the load.

Geoff---When you say "I can do it cheaper and better" and "My springs are the lightest in the business", may I take that to mean you market such a product? Can you direct me to a site, or provide contact/product info?

Besides isolation from room vibration from below, you must effectively wick the energy out of the component cabinet as well. adg101 had the cheap isolation aspect nailed! IKEA bamboo chopping/cutting boards are a no-brainer!

Bamboo composite board is rather sophisticated in its combination of polymer/grass density layering and is light, stiff, 18% more rigid than hard rock maple, and will be less likely to store low frequency energy. Not to mention, green and cheap.

The moongels may well do the trick over an audiophile BrightStar Isonodes or other gel gumdrop type footer. These are great below the board, but you will want to couple (wood blocks(to chassis/not under feet), point, etc) the cabinet/chassis of the component to draw either internal energy or airborne acoustic energy from the sheet steel box.

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.

Once you eliminate the smearing that these vibrations cause with, cheap DIY solutions, I believe there is no doubt you will be well rewarded, perhaps amazed by the results. Your system background will become way blacker as well. I’ve employed these methods for years on my digital course, tubed preamp, and tubed phonostage with excellent results. I realize your Atma pre offers very little room on top to try to mass load, is it the UV-1 UltraViolet?

Happy Listening!

With a preamp that light, just like a small phonostage, or DAC, what-have-you, you need to be aware of not "loading" the preamp chassis with a heavy mains cable dangling from it, causing an energy path from whatever the cable is also in contact with. Again this is where those shot filled bags could be placed above and below the mains before it enters the preamp to "unload" its effect.

"Geoff---When you say "I can do it cheaper and better" and "My springs are the lightest in the business", may I take that to mean you market such a product? Can you direct me to a site, or provide contact/product info?"

I've been in the business of isolation and vibration control for 20 years as well as many other things.  Currently I offer small steel springs of different spring rates for isolating anything from one pound to 250 pounds. These springs are very low profile so can even be used on submarines.  ;-)

Geoff Kait
machinadynamica.com