Look at the Adona racks. They combine granite with MDF and a special adhesive to (supposedly) get the best of both. I use one, and really like it, but I have no way of knowing what might be better for you. I know that it is much better that MDF, or thick slate, because I tried both. You should also definately check out Starsound Technologies. The good thing with the Starsound platforms is that you can use one that fits your CD player on your existing rack.
On what do you place your AA Capitole Reference SE
I have placing my AA capitole Ref CDP on various platforms like MDF, Plywood, Granite and sometimes combination of some of them and every time I hear a very drastic change in sound. I am yet to nail the right kind of platform for this player. I have tried putting the player under Symposium roller blocks but that is making it sound lean. Wood sounds good but slow. Granite sounds lean and tad hard. I am really confused on what should be the platform like. Sacrificing tone for speed or vice versa is not at all ideal considering one has spent $10k on a CDP. I am sure there must be some solution which sounds good overall. AA users please share your opinion on this. If required I can get custom built platforms, just need suggestions.