Two very different solutions to the same problem.

I definately noticed a big imporovement when I binned the stock feet for Dave C's 'squidgy' feet and place the Techie on a proper Target wall shelf. The shelf itself uses a thin-ish sheet of glass which is decoupled from the metal frame by four squashy rubber buttons.

I've not tried any other alternatives, but possible options would be a slate slab to replace the glass and that hard contact points (such as Stillpoints etc) between the shelf frame and slab and/or the slab and Techie itself.

I'll get around to experimenting at somepoint, but my gut feel is that with a turntable where presumably it's more about stopping energy getting IN that sinking energy OUT, I'd have thought that damping and isolation would better, but I don't really know.