I use an 4 inch thick block of mango wood, sitting on top of four 1 inch square erasers from the local school supplies store. This all sits on top of my teak stereo cabinet. Not a hint of vibration.
Turntable isolation
I have my TT (Rega P7) on top of my audio cabinet. The cabinet is an Ethan Allen Townhouse component cabinet with a marble top. I noticed this weekend that when I touch the doors to my audio equipment I can hear a light thump via the cartridge. Even when I lightly tap the door the sound travels through the cabinet woodwork, through the marble to the cartridge. How can I isolate the TT from the rest of the cabinet?