Maple platform under turntable, How thick?

I was happy with my a la Mapleshade 4" maple block on cork/rubber pads, untill I decided to try (based on A-gon thread) aluminum top plate on sandbox. Bunch of transistor heat radiators are bolted to the bottom of 3/4" anodized aluminum plate and submerged into 30 kg box of sand - all unwanted vibration are completely sunken through the huge contact surface and died out naturally in the sand . The whole thing is supported by 6 big and thick sorbotane pucks - look at the sorbotane site how to calculate the optimal geometry of the sorbotane pads to minimize natural frequency of the whole assembly.
I got much jucier sound combined with ink-black background comparing with the maple platform - I guess I'm done with isolation platform.

I had vibration problems with my turntable on my raised wood floor. I had to sneak up on my turntable to keep it from skipping. I replaced my old rack with a Steve Blinn rack here on Audiogon with 3 inch maple blocks. Now I can walk up on the turntable without any problems. The sound from my whole system is much better from the new rack system. I would recommend the 3 inch maple blocks.

As thick as a tombstone.

Whatever thickness you can get, I would suggest buying a bunch of squash balls and putting them underneath. It's kind of like a cheap man's Ginko cloud, but with a maple flavor to it. You'll probably need at least 8-9 balls for the weight.

One of the better things I did for my TT.

Enjoy,
Bob

Anyone used Polycrystal amp stand under turntable or tape deck?