Vibration Control for Lightweight Tube Components

Lowrider, I’d suggest trying Mapleshade Isoblock 1’s, or the lower priced generic equivalent that I think may be findable at Home Depot or elsewhere. Assuming that their 1.75 inch height can be accommodated. I say this even though the description recommends that they be used only in conjunction with isolation platforms.

Also, are you certain that the mechanical pathway by which shelf vibrations are affecting the preamp is not via the interconnect cables that are connected to it, that are probably resting on the shelf behind the preamp?

Best regards,
-- Al

Al wrote,

"Lowrider, I’d suggest trying Mapleshade Isoblock 1’s, or the lower priced generic equivalent that I think may be findable at Home Depot or elsewhere. Assuming that their 1.75 inch height can be accommodated. I say this even though the description recommends that they be used only in conjunction with isolation platforms."

Ah, the age old conundrum, should I isolate or should I couple?

;-)

The cheapest way to get great isolation: two Baltic Birch plywood shelves with a barely inflated bicycle tire between them, with a trio of roller bearings between the pre-amp and the top BB shelf (this design courtesy of Barry Diament). If you have the dough, a Minus K platform ($2500 or so). Alternative: a trio of the Townshend Audio Seismic Pods (about $750, I believe)

"The cheapest way to get great isolation: two Baltic Birch plywood shelves with a barely inflated bicycle tire between them, with a trio of roller bearings between the pre-amp and the top BB shelf (this design courtesy of Barry Diament). If you have the dough, a Minus K platform ($2500 or so). Alternative: a trio of the Townshend Audio Seismic Pods (about $750, I believe)"

i can do it better and cheaper. The issue with the bicycle inner tube approach is that the surface area of the air bladder/spring is too large relative to the volume. To maximize isolation effectiveness the surface area of the air spring or bladder must be minimized. Besides, a barely inflated inner tube doesn’t provide sufficient pressure/spring rate to actually do anything. That’s kind of the whole point of mass on a spring isolation.

Thanks everybody for the input so far, but I have a theory...
both preamps have exhibited the same problem; both have an exposed tube design on top of the unit.
The preamp sits on a shelf enclosed in thick wood (pine) open in front and back. If the shelf is tapped on, it may create resonances surrounding the unit thru the sides and shelf above it. These resonances may be picked up by the exposed tubes which are in close proximity. (The shelf is 10" high with enough room for air to circulate).
That would explain why a 30 lb. Rogue preamp picked up noise from tapping on the shelf. Does this theory make sense to anybody?

@geoffkait
 Ok thanks, I understand the concept of "mass on spring" now. In addition to the Mapleshade Isoblock 1, following this concept, there are Bright Star IsoNodes for isolation...

http://www.audioadvisor.com/prodinfo.asp?number=BSISO&variation=L4
IYO, would these be a good size and provide the right amount of spring rate?

@almarg ,
Al, as a test I used a wad of bubble-wrap as a cushion under the IC's and was unsuccessful.