At one time I had four slabs of 3 inch machined Granite and used them under amps, preamp and turntable. After experimenting with them (damping) in every possible way, I sold them. Could never completely eliminate the signature they imparted into the music.
Next I tried Neuance shelves, then 2 inch marine plywood shelves laminated with decorative finish, finally settling on 3" solid maple butcher block. I had the top and face covered with Westinghouse brand laminate in a semi flat gray color.
The Maple butcher block probably has a signature as well, it's just more natural sounding in my system. Perhaps trial and error is required for each person to get it right.
Next I tried Neuance shelves, then 2 inch marine plywood shelves laminated with decorative finish, finally settling on 3" solid maple butcher block. I had the top and face covered with Westinghouse brand laminate in a semi flat gray color.
The Maple butcher block probably has a signature as well, it's just more natural sounding in my system. Perhaps trial and error is required for each person to get it right.