Platform for amp

Which is better granite or maple?I will be putting the platform on top of an oak entertainment center.
IMHO neither. Both will transmit vibrations in both directions - I would opt for some isolation materiels which would reduce or eliminate the transmission of vibrations, especially if you referring to tube amps.
Definitely not granite, it stores energy and it rings. I plan to use maple butcher block on Walker Audio Valid Points with my tube amps (100lb monoblocks) based on what I've heard in other people's systems.

Alternatively, many people report great success with platforms that will not store energy such as Neuance shelves from Greater Ranges or Sistrum platforms from Star Sound Technologies. There are others.
As much as I was enjoying my system it got even better when I placed my 845 tube amp on maple with brass cones. The improvements were even more substantial when I did the same with my tube pre. Good luck.

I like the Sound Anchor amps stands. They look and sound great and can be tweaked using Vibrapods between the amp and top of the stand and replacing the spikes with Audiopoints or your favorite cones.

Disclaimer: I'm not affliated with or sell any audio/video equipment.
Or you could just cut yourself an appropriate sized piece of 3/4 inch MDF which you can get down at home depot. Cover that with the sound damping vinyl sheets you can order from Parts Express and for a whopping investment of about $40 you can achieve what otherwise might cost you hundreds, even thousands for the voodoo audiophile solutions.

Thanks Nick--Now tell me do you work at HD??--Juss kid-in.---I does sound good and reasonably priced. BTW; I just talked to 'Clara' and she don't want me doing non of that VoDo stuff---and maybe putting her out of business.
I decided on a maple platform.What should I put between the oak entertainment center and the maple block? I was thinking maybe felt.
Check out iso-blocks the rubber-cork-rubber thing as there popular with the maple platforms. Search the classifieds under tweaks and you'll see one person selling four of them for $10.00 there are a few that try to get $25 a set. Happy new year to all
Here is what I did guys.I bought the required material from a company that specializes in metals.A.S.A Alloys. They sell
stainless steel,nickel,aluminum.They deal with big orders though.I used 1/2" thick aluminum angle line sized @ 4"x6".
I cut four lenghts @ 30,1/4" long.I braced each set together with 2"x4" aluminum tubing.I drilled and tapped two 1/2" holes under each angle's 4" side.Thats where the 1/2"threaded feet are going.The final product looks massive and very impressive.So I made two amp stands with overall size 20,1/2"wide by 30,1/4" deep.Height including the stainless feet is 7,1/2".
Top platforms will be made out of maple and will be resting on the aluminum stands on brass cones.All my connections are with stainless steel screws to keep it non-magnetic and the tubing could be filled with sand or lead.Allthough that would make them very-very heavy.They are HEAVY now even though empty.
How about a picture? It sounds like you did a good job with construction.What is your system like?
You went to a lot of trouble for this "amplifier platform" only to screw up the sound by placing it all on top of a high mass entertainment center. And when you factor in the havoc that is being wreaked on the rest of your components with this behemoth, you can imagine what the end result is. Do yourself a favor and buy a decent equipment stand before you go playing around any more with isolation devices.

I agree with Oz. I had my CD transport and D/A on an entertainment unit, and was amazed when I tried them on my wall-mounted turntable stand; the sound was much cleaner, and with more detail all through the spectrum. Out went the entertainment unit; I bought some Atlantis Symphony 1 stands, replacing the supplied MDF shelf (sounds horrible) with plywood. Unfortunately Atlantis no longer make that stand; instead they make something with an integral MDF shelf.