They did little for me but the best place I found for them was under the turntable. The sand compacts under weight to a solid base.
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I have yet to beat my DIY sandbox with my Scoutmaster. Many are using sandbox isolation with their VPI's, most seem very satisfied. Tried various suspension type isolation schemes, didn't like those at all, I suspect mass loaded designs like vibration drainage. Sand and aluminum together do a first rate job, check out the Galibier tt website (DIY sandbox design, or could use this with commercial sandbox), Thom had my solution. I think you would have to spend a lot more to get much better, something like the Grand Prix line.
I had my Super Scoutmaster on a Target wall mount but was getting the onset of feedback as the volume went from loud to pretty loud (I have a Vandersteen 2W sub 5' away). By putting a Symposium Super platform ,on the Target, with three Rollerblock JR.'s between the table and the platform I was able to eliminate the feedback completely. Can now crank up the volume (with the stylus in groove and platter not spinning) with no hint of the former feedback/howling. Absolutely worth the expense!!
I have built a number of sand box type shelves for various systems over the years. I do think they can sound good and are a good approach for DIY. I built a very nice set of amp stands that looked great and sat under a set of tube BAT VK150SE monoblocks I had. I also had another system that had a set of Pass Aleph 2 monos. I had a set of stands I had built for the Aleph 2s that was a box but instead of sand I used a small inner tube under the top platform. After getting some Grand Prix Audio amps stands for my BAT amps (which by the way were hugely better than the sandboxes) I decided to try the sand box stands under my Aleph 2s since they looked better. I hooked them up and man something was wrong the sound just wasn't that good at all. I didn't even think about the stands, but I just new some magic was definitely MIA. Well finally I switched back to the inner tube the sound came back.
So the verdict that I have came to is that you never know. I know for a fact that isolation can make or break a system, so for any reasonably good system I don't mess around with homemade sand boxes
If you can someway find yourself a vibraplane that is a huge upgrade for a turntable or any component for that matter.
J Loveys, I did see your pic on line and it did catch my eye. How do you level the table? Did you have a sand box before the Symposium? I have quite a few symposiums in my systen and do like them quite a bit. I wonder how much better it would be than what I currently have (what I have sounds awesome). I also wouldn't want to give up the ability to level, so I wouldn't be direct coupling the plinth to the base, but, rather, keep the table on the feet and have the feet rest on the symposium. I currently don't have any feedback, nothing skips when I walk or jump up and down in the room, and can tap my finger pretty hard on the plinth while a record is spinning and needle is in the groove and there isn't any sound (of the tapping) at all. Appreciate your input.
Dear Cerrot: the Ultra platform is directly on a VPI thick wood platform that has large leveling stainless steel cones , so I level the TT with them. Direct coupling the VPI makes it unsuspended and in this case it is a big improvement sonicaly over the VPI air feet suspension. I have tryed both ways and this is superior. I do use my stetoscope to eliminate any motor rumble, it is quiet, steady and external vibrationproof. A very important thing is to couple the underplatform with the wall with strong angle-iron . There shoudn't be any motion when pushing the platform sideways, especialy with wood floors. The pen tapping test on plinth and platter is dead silent too.
I have not tryed sand platforms but the VPI stand feet are filled with sand, this makes the whole thing about 150 Kg! I am working to replace the acrylic TNT plinth with a slate plinth ,...
AFAIK, a sandbox with a segmented top plate is the only platform that can completely isolate all the TT elements from each other, while preserving a fixed, stable geometry between outboard motor, flywheel, and plinth. Any other system will tend to recirculate vibration across the horizontal surface of the platform.
Isolated segments of a top plate come at a cost - that of maintaining the correct speed relationship between the drive system and the platter. You might get better isolation, but it doesn't come for free.
In Galibiers (and by inference Teres, Redpoint, and ???), every time the coupling between motor and platter has improved, so has the sound.
Now, just like rubber belts in some designs, the net result can be an improvement. I think what we're looking at here is: (a) how much vibration you're sinking, and (b) does any of the movement inherent in this isolation strategy get masked by any compliance in the belt.
The bottom line is that there are no absolutes and the entire system needs to be considered as an ecosystem. What works in one context will not necessarily work in another.
On a related subject (and one I feel more absolute about), from time to time I find myself working hard to convince customers to NOT site their drive system on a separate stand from their turntable.
Picture two sky scrapers independently swaying in the breeze, and I think you can visualize the nature of the problem. Since no two areas on a floor vibrate identically, the two stands will move out of sync with each other. The higher the stand (in relation to its width and depth), the more this is exacerbated.
That's my story and I'm sticking to it ;-)
Thom @ Galibier
Thom @ Galibier
Thom, Segmented top plates sharing a single sandbox, each segment with an alumimum angle or aluminum heat sink anchored deep into the sand. Heavy mass-loaded plinth with heavy outboard motor. Do you really believe that the top plate segments will move relative to each other enough to cause even tiny shifts in geometry of drive train?
I can tell you from my own experience the single aluminum plate using the vibration sinks, per Thom's instructions, is superior to the segmented top plates I've tried. More refinement, resolution, more slam, solidity, greater dynamics. Now, I've thought about segmenting the aluminum plate, Thom's argument makes sense, I will not segment.
Do you really believe that the top plate segments will move relative to each other enough to cause even tiny shifts in geometry of drive trainYes.
Based on the argument that these two pieces won't move independently, one could argue that isolation of any sort wouldn't help because all of this movement is so minute.
Ultimately we are all patently mad and arguing over small things, but as long as we're having fun with it, let the debate rage on.
Thom @ Galibier
Assuming that significant mass loading has been applied to minimize shifts of the segmented top plates in the horizontal plane, the heart of the matter would seem to be that vibration is conducted through dense adjacent solids--in this case, mechanical energy moving in the vertical plane from plinth to footer to wood plate to sand. In a related twist, tonight I modified the suspension of my modified thread-drive VPI TNT to incorporate DIY Stillpoints inside the elephant feet (which are otherwise unsprung.) The mod consists of a pyramid of ceramic balls, supported by spring steel petals that dissipate vibration of the bottom tier of balls into the horizontal plane as mechanical energy. The result was a rather amazing improvement in coherence and general sonics. The operation of the ball/spring combo would seem analogous to grains of sand beneath the sandbox plates, but in the horizontal rather than vertical plane. Now I will bet my eye teeth that those balls & petals in the Stillpoints are by design moving more in the horizontal than the segmented plates in the sandbox-- and yet sound is significantly improved. You would have to put up a pretty strong argument that the improvement in sound represents a compromise between improved resonance control and degraded speed stability.
Dave, the sand should move in both the vertical and horizontal plane as well,
It still seems to me a mass loaded design should sit on the most stable platform you can provide, seems some non-sympathetic vibrations would be induced by more compliant platforms. Therefore, vibrations of different parts of the tt are moving asynchronous to each other, inducing confusing movement to the entire mechanism. Sitting on segmented plinths should only increase this confused movement.
I should add, every move I've made towards a less compliant plinth and more massive platform has resulted in increased sonics, specifically, much more coherence, solidity, slam and bass articulation. Any compliance sounds smeared and soft.
I plan on making a 10" sandbox this summer to gain yet more stability and mass. I'm also trying to find some wider aluminum L brackets in order to get more vibrational drainage. I always think about the massive plinths and platforms of the Brinkman and Continuum tts, I'm sure a lot of their superior sonics come from this mass and the stability it imparts.
"Any compliance sounds smeared and soft"Lest the good folks misinterpret your comment, I'll embellish a bit.
The improvements rendered by reducing compliance result in both cleaner and more extended highs. There is nothing agressive sounding about the extended top end when you get this right.
Furthermore, the improvements are experienced as a richer, harmonic texture in instruments like acoustic bass. Bass texture is, after all about the upper frequency harmonics.
Again, it may well be that on some rigs, that isolating the motor can help in the way that a compliant belt can. Before you accuse me of heresy, hear me out.
In some AC motor experiments our little group of crazies has been undertaking, we positied that some of these drive systems might best be implemented with a compliant belt. There was too much vibration in the system.
Of course, we were looking at optimizing something that none of us would consider swapping out our rigs for, but the point is about trying to optmize given architecture.
There are no hard and fast rules. This was the source of my "ecosystem" comment and is the reason I'm not absolutist about one piece top shelves for the entire population of turntables.
I'm working on a source for some very stiff "L-brackets" which I used to source at an aluminum recycling yard. When I get the name for them, I'll publish it on both the shelf and stands FAQ section of my website as well as on the accessory page showing the sandbox made by Timber Nation.
Now, if you hang out at any electronic surplus houses, you might find some big honkin' heat sinks. I've come across some which are 6" x 8" and have some under my main sandbox.
Thom @ Galibier
Scott, I agree that sand moves in all dimensions at the particle level to dissipate system vibration as mechanical energy. The issue is somewhat different regarding drive train stability: Will the segmented top plates migrate or resonate in the horizontal plane in sympathy with transient pulling forces of the motor belt? Will any associated micro shifts in drive geometry introduce speed instability sufficient to off-set the virtue of improved isolation provided by a segmented top plate? One can only speculate on these matters until trying both arrangements with top-plates made from identical material.
Material composition is an important factor. For example, I first installed my DIY Stillpoints in cavities drilled inside the stock VPI delrin feet. Internal vibration was conducted from TT plinth to solid brass spacer plug(replacing stock sorbethane) to ceramic ball pyramid to spring steel bearing cup to delrin foot to wood to sand. Each modification was evaluated separately and was determined to be a sonic improvement. But the greatest improvement occurred after the final step of adding a brass core inside the delrin footer that directly couples the bottom of the ceramic ball bearing cup to the segmented hardwood top plate in the sand below. There is insufficient mass in this brass core to be significant as a vibration dump. Relative to delrin, the brass core must therefore be acting as an improved conductor of vibration down to the sand.
One might conclude that your aluminum top plate is performing a similar function as my brass core. Did you ever try the thick aluminum plate by itself to detemine if the plate is acting primarily as a dump, or as a superior conductor of vibration? If the sand adds any sonic improvement as compared to using the aluminum by itself, then one may conclude that the aluminum is performing as a conductor. And if the particular virtue of aluminum is its performance as a conductor, then one may speculate that your alum top plate also operates as a conductor of vibration in the horizontal plane between respective footers & motor. A superior conductor like an alum top plate might therefore benefit from segmentation more than other material compositions that tend to act as dumps. Segmentation may act to draw off the kind of "asynchronous" vibrations you alluded to above, that confuse a closed system where vibration is both generated & recirculated.
While it's nice to talk about reducing compliance as a absolute goal, I think this idea should be revisited in light of recent experience of jloveys and myself concerning the sonic virtues of Symposium rollerballs, Stillpoints, or my DIY version of same. These devices are designed to MOVE in horizontal, vertical, or both. I wanted to explore this with my recent TT experiment, and the results seem to suggest that mechanical systems like TTs need to "breathe" a bit to release energy. The result of this experiment is improved HF focus & smoothness, delineation of bass, and precise but rounded images-- anything but brittleness, softness or confusion.