If there is one thing that I learn about all vibration, it is that mass helps a great deal. My present turntable weighs a hundred pounds and needs to be on a rack. It was a beast to get it there, as I was the only one around. At first I was somewhat disappointed with it until I realized that the Ikeda 407 tonearm was not very tightly mounted on the special mounting boards. So rigidity is also very important. But I suppose that with enough weight even rigidity might lose it importance to some degree.
I once had a Final Audio turntable which was solid copper with a 6 inch thick copper platter and substantial solid copper bearing. This assembly weighed 285 pounds. It just sat on the mounting board as did the column for the tone arm. It was thread driven by a substantial motor. There was no isolation at all. And it sounded fantastic when on my slab floor. It was nowhere near as good on a wooden shelf.
I once had a Final Audio turntable which was solid copper with a 6 inch thick copper platter and substantial solid copper bearing. This assembly weighed 285 pounds. It just sat on the mounting board as did the column for the tone arm. It was thread driven by a substantial motor. There was no isolation at all. And it sounded fantastic when on my slab floor. It was nowhere near as good on a wooden shelf.