TW Raven Owners: Set Up Questions

Thanks for the tips. The slate is a stop gap measure until I can find something better. It can't be worse (can it?) than the single sheet of MDF it's on now. I have it atop a Naim Fraim set, which are designed less for mass loading and more towards light weight isolation/dispersion. I have a feeling adding significantly to the shelves mass will defeat their purpose. I may be headed back to using a wall shelf. I have one now but it wasn't installed to handle a 50 lb. Raven. I will have to re-engineer its placement if I decide to use it again. I would contemplate a SRA, Symposium, etc, but I'd really like to be able to try one first so I can decide if I like it's effect. At least with the granite it only cost me $20.

It's hard to beat a wall-hung shelf (especially if mounted on a masonry wall) for reducing the effects of structure-borne feedback?

I use factory bench with 4 inches slap of black granite right now with my TW. I have a friend that in the past had tried quite a few different types of stone for amp/speaker stands etc before and he found best result using black African granite (supposedly it has higher density than average granite!) In the past I tried slate but the result was not great. At least for those that I could find locally anyhow. I was trying to get a quarry to cut me pool table slate slap and it was a big hazzle and trying to get them to polish slate smoothly was almost impossible (may be I need a pool table factory for this). Anyhow, the one I got was not so great. However, I just located a used Symposium ultra locally that is big enough for my Raven AC-1 so hopefully I will try that in the next few days.
Vibraplane is also something I want to try or perhaps Minor-K. However, I am still thinking that eventually I might try to get BN 3 motors unit for my Raven so until I know for sure what size the turntable platform will need to be, I don't want to invest a lot on platform for my turntable just yet.

I use a wall shelf and have tried a number of isolation feet. The problem with heavy granite slabs is the wall shelf might be overloaded. You don't want the table falling off the wall.
I have used a number of feet, stillpoints, black ravioli, Herbies Isocups. the New stillpoint SS Ultra are marginally better than stillpoints+ risers, not enough to justify the added cost, but better

In addition to the above, granite can be OK if damped by gluing linoleum to the underside.