Congrats on your purchase. I would ask the manufacturer.
http://www.kineticsystems.com/page.php/id/157
Lets us know how it works out.
Brad
http://www.kineticsystems.com/page.php/id/157
Lets us know how it works out.
Brad
Vibraplane: Should it be loaded close to limit?
Dear Peterayer, any vibration isolation platform does only work at its best when operated as close as possible to its maximum payload. Right now your Vibraplane doesn't work at all. You should consider adding a very heavy grantie or similar load plate underneath your SME to get close to the payload maximum of your VP. When you look up the technical specifications of the 2210 on Kinetics website, you'll see how the resonance frequency is related to the payload. For some insight you might contact Audiogoners Syntax or Solong. Both do operate the 2210 since years and have fine-tuned their VPs payload over the period and with telling results. Cheers, D. |
4est is correct ... simply place your 30 lbs TT on top of V/P ... pump up bladders and then bleed them individually until the top of the Top Plate on the V/P is 3 and three quarters inches (3.375) from the top of the shelf that the V/P is sitting on ... no extra weight needed If you change a component that weighs more or less ... just pump up V/P and re-adjust to 3.375 At 3.5 my system sounds fat and at 4 it sounds lean and lifeless Gently bleeding bladder to level V/P will bring new meaning to the word frustration ... you will learn to curse in many new language's you didnt know you spoke |
Sure you can work w/o extra weight. And it still does some good for your sound. If you're satisfied with 60% performance - than you are fine. If you want the full benefit from your Vibraplane (read: lowest possible resonance frequency - as this is what the complete vibration isolation issue is all about), you will have to go as close to the maximum payload as possible. Sorry - not my idea, but physic. You may ask Audiogoner's Syntax or Solong about their journey with standard Vibraplane and then with added weight till maximum payload was approached. They will tell you that you just can't argue with physic and how much the sonics - especially in the low and lowest registers improved. Cheers, D. |
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've been poking around the web trying to come up with a BOM list for building something like this. As it turns out, even though I already have a compressor it would cost me at least $1200 just in parts to get the features of the 2210. Here is a spec sheet for an air spring similar to what is used in the Vibraplanes. The graph at the bottom shows the information Peter was looking for, just not specific to that exact product. Still, we can see how adding mass moves the frequency at which damping is the least farther down the graph. Neat stuff. Air Spring |
Thanks for digging this up Pete, much obliged. It certainly is an interesting unit. Since my table weighs around 120 lbs, I've also simply placed it on top of the Vibraplane. The active system makes leveling a whole lot easier than the passive version I'd guess - mine maintains level perfectly once you set the three thumbwheels to the correct height (I'm at 3.75 inches for now). The compressor kicks on once every six hours or so, so I either have a very very slow leak, or that's just how it functions...comments on the interval of compressor cycles would be welcome. The compressor is a Jun-Air, and is the most silent air compressor I've ever experienced - you only hear it click on and off; I think they were designed for dental offices. My initial impressions are of a drop in background noise by several orders of magnitude, not a softening of the sound, but rather a very black background. Low frequencies certainly have better control and articulation, especially way down low. My concern at the moment is the nature of the top plate itself - given that it's non-magnetic stainless steel, the same material as the cones on the bottom of my deck, I notice a bit of stridency introduced into the upper midrange, a quality that was absent with my aluminum top-plate sandbox. I'm guessing I'm getting a bit of 'chatter' due to the two equally hard materials interfacing with slight surface imperfections exacerbating the situation. I'm going to experiment carefully with intermediary materials between the deck and the Vibraplane, either substituting cone material or introducing another shelving layer between the two. At 180 lbs, the Vibraplane is a two man lift to be sure, so haphazard swapping in and out is not on the agenda. It will be a while before I solidify my thoughts on what, exactly, it brings to the table over alternative isolation methods, such as my beloved sandbox. |
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. |
Great feedback, guys! Richard and Peter, I'll be interested to hear your thoughts on auto load leveling and the lack thereof as you guys get more time with these units. I'm interested to know how well each unit holds pressure, and how often they need to be leveled in normal use. A passive would certainly be easier and cheaper to build. These commercial air springs have stiffer side walls which give them an advantage over simple air bladders. Richard, can you see a way to add a valve in the airline just before the Vibraplane? I assume there is a pressure gauge in the vibraplane. Closing that after pressurizing may tell you if the slow leak is in the unit or before. Does it bleed off air normally as part of the leveling? I'm not sure the compressor running every 6 hours or so would be enough to build up moisture in the air lines. That is the only reason I would even think about how often it cycles. I also wonder if it could be sufficient to run one off of an air bottle in a closed system. Don't laugh at the bathroom scale trick. We used to do that with our race cars to set the suspension. One scale under each wheel. Obviously, these were pretty light cars. |
Dan, Indeed the Vibraplane uses a type of air spring which I think contributes significantly to its excellent horizontal isolation; they are not mere bladders, or else I'd just do the inner tube trick and be done. The compressor has a regulator and moisture trap, and the Vibraplane has its own regulator valve as well. Alas, I traced the leak back to the unit itself, and not the air line(s) on or from the compressor. While I am uncertain if it's actually an air spring leaking or one of the leveling regulators (for lack of a better term) it still means having to flip it over to find out - soapy water at the ready. There's also a lot of air tubing running all over the place under there, so it could be that as well. Needless to say, I'm going to have to return to the sandbox for a while until I can pin down the problem. Of course cajoling friends into helping one heft these things around usually takes a free dinner and plenty of beer...ah the lengths we go to for this hobby. |
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. |
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. |
Peter, I just replied to your email. That looks really nice but I'm partial to black. :-) I see you answered my question about the total weight now on your VP. Your findings make sense regarding loading closer to max rating. IIRC, many iso devices show graphs of the increased isolation as the load gets above 50, 60%. Scott probably has forgotten more info about this than I have found. Things like this keep putting off my Loricraft. |
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. |