Vibraplane: Should it be loaded close to limit?

The passive unit I just bought cost about $250 to air freight from the West Coast to the East Coast. Rather expensive. Kinetic Systems is in Boston and Sounds of Silence is in NH so that is certainly a more economical option if one can find one used.

I do find the filling and releasing of air manually takes a bit of getting used to. The process took about 10 minutes for me to set up initially, and it is holding level 24 hours later. The three feet are each about 1/8" over the edge of my top shelf on my Zoethecus rack, so I am looking for a large slab of granite to put under the unit to distribute the load directly over the vertical legs of the rack. The added weight at the top of the rack is not good as you can imagine the pendulum effect.

I also started looking into pre-loading options and am getting prices for 24" X 20" slabs of granite, marble and steel of various thicknesses. I hope to have a slab in the 100-125 lb range to play with pre-loading.

Vibraplane does make a newer type device which only weighs 45 lbs, has a smaller footprint and seems to be more user friendly. I've never seen one used, but there is an excellent review in Positive Feedback.

Dan, my passive unit can be filled up with a compressed air tank/canister. This may be easier than the hand pump, but it still will not have the automatic self leveling feature, which could be very convenient.

"Indeed the Vibraplane uses a type of air spring which I think contributes significantly to its excellent horizontal isolation."

The original VP reviewed by Stereophile used elastomers for horizontal isolation and an airspring for vertical isolation. Has this changed? I could find no information on their website.

no it has not changed, the horizotal isolation is what we call a slip-plate technology which is one reason it needs mass to work properly.
Steve
SOS

I just added a 24" X 20" X 1" steel plate for ballast on top of my
Vibraplane. This pre loads the unit by 136 lbs. With the 35 lbs from the
turntable, the total weight now is 171 lbs on the Vibraplane. This is
considerably more than the turntable alone. The Vibraplane is designed to
take a maximum load of 275 lbs.

The added ballast made a significant improvement in overall sound. One
analogy that comes to mind is how my truck rides smoother when the
springs are loaded with cargo in the bed of the truck.

Isolation has increased resulting in better retrieval of low level information. It
just seems like more music is coming off the grooves. The sound is bigger,
bass is deeper, strings and cymbals are smoother and better defined. Noise is
lower so dynamics have improved.

It is an across the board improvement about as big as the difference between
the Vibraplane and the Townshend Seismic Sink it replaced. This isolation
may well be what separates my unsuspended SME Model 10 from the bigger
suspended SME tables.

Photos of the steel plate can be seen on my system page detail images of
SME and Vibraplane. It is a very worthwhile improvement.

Great job Peter and nice to hear again what loading can do when using a light weight TT or CDP.
Enjoy