Butcher block acoustics makes affordable and good looking isolation platform made of wood, maple or walnut. Been using them for years to good effect. Can be bought with or without metal threaded inserts for the feet of your choice, which they also sell. My latest in maple replaces an existing wood shelf that came with my turntable wall mount, so no inserts and no feet required, as the isolation rubber feet are integrated into the turntable wall mount. The wood is very hard and so I can do without the tip toe discs on the turntable. Wood is a far more "dead" material than metal. Not sure why one would consider metal. Between the added butcher block, the dual plinth design of the turntable, the TT tip toe feet, and the fact the shelf is bolted to a concrete outside wall which faces the back of house, and away from "possible" street/traffic induced vibrations etc....not sure I can better my set up much. Plus the shelf is up high, eye level when standing....well above speakers. I tend not to worry about so called seismic vibrations, unless there is a 6 on the richter scale. 😁
