Home grown turntable platform/base?


I picked up a used Pro-Ject Debut Carbon turntable for the family room. We are not big into vinyl, mostly listen to digital, but my 16yo daughter has shown an interest in getting some records. I’m getting excited about her interest in vinyl and audio. What is a good platform material to use? Wood? Granite? Should I add sorbothane and/or spikes underneath? I’m not looking to spend a lot but feel I should have some decent isolation for it. The turntable currently sits on a hollow shelf. It’s where it has to be so I need to make this work.

Thanks for any input.
asahitoro
Awesome advice @noromance. Thanks again to you and everyone else. I'll post what I end up with.
+1 on thick butcher block. Even better, Mapleshade makes some great thick solid maple plinths.
Thanks Steve,

I'm digging this Mapleshade unfinished block:
https://shop.mapleshadestore.com/18-x-15-x-2-Ready-To-Be-Finished-Maple-Platform/productinfo/18X15X2...

Would this be a good combo with the Herbie's Tenderfoots or would the granite/spikes route work out better?
This is exactly how my daughter gained an interest in vinyl. Same age too. Started with the project and that led into a VPI prime signature. 

We use the butcherblockacoustics platform. Nor very expensive a beautifully made.

It's amazing how 3 years later my daughter has collected over 100 records of her own. Met Michael Fremer and has been to numerous audio shows and shops. 

Enjoy 

Regarding has2be's statement that screwing the two pieces of birch ply together will defeat the isolation provided by the constrained layer damping placed between them, that layer of damping material is put there not to provide isolation for the turntable, but to absorb and dissipate the resonances of the plywood itself. Green Glue, ASC Wall Damp, and EAR Isodamp is too thin to provide any isolation. It is the springs, roller bearings, Herbies feet, or Seismic Pods (or even slightly inflated inner tube) placed under the shelf that provides isolation, not the constrained layer damping.

No harm in trying the two pieces of ply both screwed together and not, though. However, Green Glue doesn't completely harden, which would allow the two pieces of ply to slide around in relation to each other a little. ASC Wall Damp is tacky enough to keep the pieces of ply from sliding against each other, but EAR Isodamp isn't; if using it, the two pieces of ply will have to be attached to each other in some fashion, ergo my suggestion of screws. Since the ply/constrained layer/ply construction should function as a single unit, you actually WANT the two pieces of ply to act as one. The reason for using two is to increase the stiffness of the shelf, and to allow the installation of the constrained layer damping, to make the shelf less resonant.

If you want a layer of isolation-proving material between two outer layers of stiff material, the Symposium shelves are the way to go. They have outer layers of stainless steel, with a thick layer of foam between them, to provide isolation. Symposium makes a version of their shelf with springs attached to the bottom, specifically for turntables. That model is relatively modestly-priced, around $350-$400 I believe.