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Dumped the rack

So I have a steel spiked Sound Organization table about 2 feet tall. On it rests a 3" maple butcher block. On that rests my slate Garrard 401 with slate feet and aluminum cones.
I had a piece of granite made and installed it on the maple beneath the turntable. Man, that sounded bad. Silvery colored and dull. I reversed the layer order and put the granite below the maple. That sounded a lot better. But not as good as when there was no granite. So I took it back out. Okay back to how it was. But something was missing. The granite did bring a feeling of stability to the image. What to do? I took the whole rack thing out of the equation and put the 401 on the concrete floor along with the preamp. This sounded best notwithstanding the wooden tone lost by removal of the maple. But the best thing, and I’m aware of the effect from reading but never tried it, was that imaging has improved by quite a margin. Like removing a veil of something. Like when someone moves their head out of your face at a concert. Now, I have to bend down to play records. 
noromance
noromance's avatar
noromance OP
10,198 posts
 
Tom, I'm inclined to agree with what you say about the rotation grounding. I do need to get the thing off the floor if only to blow fluff off the stylus. I think I'll put four 8x8x16 cinder blocks on end under the maple and see how that sounds.
@slaw Looking forward to the mat. Currently running no mat on aluminum platter. 
@thosb Racks are certainly a challenge. I'm not sure I want the table downwind of the speakers.  
slaw's avatar
slaw
23,687 posts
 
OK...my point of reference will be, having the tt at an appropriate height that a normal person can deal with all maintenance issues. IE: "rotational grounding"  I'm just a layman...…………..

Good Luck!
millercarbon's avatar
millercarbon
12,531 posts
 
Granite is good for mass and stiffness but the problem with granite is it rings, which accounts for the problems you heard. What I found works pretty good is to set the granite on a sand bed. Only a small amount of sand, an inch deep is plenty. Mixed with a little mineral oil it packs stable, doesn't scatter, and stays dust free for years. This pretty effectively damps the ringing. Of course you still do not want to put your components directly granite! Its best use is as mass, but mass that retains dynamics not mass that simply damps the way sand does. In my rack its just one element among several that work together to achieve strength, mass, and stability.

My Basis table was on the floor for years. Tried different things but the floor, even an ordinary wood one, is very hard to beat. The rack I finally came up with uses a combination of concrete, ABS, sand, granite and carbon fiber. Its better even than the floor. But not by much. With the factors Tom already mentioned going for it the floor is just awfully hard to beat!
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geoffkait's avatar
geoffkait
23,365 posts
 
You did the right thing. Racks are bad Gnus. 🐂 🐂 🐂 By and large racks exaggerate (amplify) the effect of vibration, that’s why modern buildings are constructed to prevent minor earthquakes from being amplified by the building structure. The one-mile circumference HQ building of Apple in California is built on huge slip plates for earthquake protection. One inch granite might ring. Three inch granite doesn’t. It goes thunk! Besides, what you really want to do is isolate the TT, and use thick granite for the top plate. Then the granite will be isolated, too. The granite top plate provides excellent isolation against rotational (bending forces). And use a mass-on-spring iso stand. Guess what provides the mass.
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