Vibraplane: Should it be loaded close to limit?

AVphile,
The Kinetics website quotes a max load of 200, but the specification sheet for the unit quotes a max of 275. The performance graphs suggest the closer to the max load the better the isolation figures. I have emails going to both Sounds of Silence and to Kinetic Systems for some suggestions. I just thought Audiogon members who own this unit might have some insight on how to optimize its performance.

I did hear back from Kinetic Systems and from Sounds of Silence. Tony at KS suggested I contact Steve Klein at SOS as he has more experience with the VP in audio applications. The maximum net design load of my passive 24" X 20" Vibraplane 2210 is indeed 275 lbs. Steve wrote me that there will be audible improvements when pre-loading the unit in the 125-150 lb. range and then diminishing improvements from that point on.

Neither gentleman recommended one type of slab over another but Steve did mention that a critical decision would be what material to use between the slab and the top of the VP. He recommended researching materials from EAR.

My VP arrived today and I think I will start by just setting it up as is and comparing it to my Townshend Seismic Sink. I may end up moving my TSS under my phono amp as I have another one under my pre amp and it did improve the sound. After I live with the VP under my TT for a while, I will experiment with pre-loading it. The unit weights about 150 lbs, so if I add another 150 lbs plus my 30 lb TT, that will be a lot of weight on the top of my rack.

Thanks for all the feedback and if anyone has anything else to add, I would appreciate it.

I can report some very early impressions. I set up the Vibraplane under my TT with no intermediate slab to preload the unit. The improved isolation results in a more articulate bass with more weight and, subjectively, more extension. There is a more silent (blacker) background and overall drop in noise floor which improves dynamics and very low level detail retrieval. I'm hearing spacial cues which I did not notice before as well as clearer relationships between individual instruments further back in the soundstage. In fact, I didn't really have much depth to the soundstage before. Plucked violins in the background providing a foundation for solo mandolins in the foreground for example never sounded this convincing. They are separate in space, articulate and clearly distinct. Finally, I can play the system louder without it starting to break up during complex and energetic passages.

It did take some time to fiddle with leveling the unit using the hand pump on my passive unit and I can see how the active model with compressor would be more convenient. I don't notice any chatter between my TT and the top plate of my VP as the SME TT has rubber footers and notice no such stridency in the upper midrange.

I would add that I find the isolation to be cumulative. I bought my first Townshend Seismic Sink for under my TT and when I bought a second one, I put the first one under my pre amp. Now my second Townshend is under my phono amp. I did listen to these in stages and each addition improved the sound, and the VP seems to be more effective than the TSS.

After I live with the VP for a while, I will start to experiment with different heights and preloading.

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.

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.

You are most welcome, Palasr. I've done some more listening and can further
describe the improvement as being somewhat like the difference between a 33
1/3 recording and one at 45 RPM. The stylus seems to be pulling more
information from the grooves for a more complete musical experience.

Another thing I have noticed since I have added the ballast to the VP is that the
stylus has some gunk on it after playing some recordings. I have rarely seen this
since I improved my cleaning regimen. I will have to look at this some more,
but I wonder if the isolation is now at a point where the lack of miniscule
vibrations allows the stylus to ride lower in, and more centered in, the absolute
bottom of the groove. This may result in it picking up some dirt that was
previously untouched by (below the reach of) the stylus.

This is only speculation on my part, but I'm curious if this makes sense or if
anyone else has similar experience.