Sandbox-style isolation

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 ,...

Thanks for the feedback, Jloveys. I'll keep an eye on a used ultra platform. Thanks again.

Dgarretson,

No I have not tried that, but will keep it in mind. Very interesting about cutting up the top plate to isolate each component foot.

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.

Hi all,

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 ;-)

Cheers,
Thom @ Galibier

Cheers,
Thom @ Galibier