DIY Isolation Platform

Drain and isolate are two different concepts. Drain removes internal vibrations and isolation prevents external vibrations from entering (as well as keeping internal vibrations trapped). I would not recommend using cork or rubber next to the component since that will trap (isolate) the vibrations internally. Symposium makes effective platforms that do both by using a metal to drain (remove) internal vibrations and foam to isolate and convert vibrations. Try using a piece of stainless steel (non-magnetic) on top of wood along with SS couplers. Or use aluminum if that's easier to get you hands on.

What are SS couplers?

A concrete paving slab on top of a 4-6" foam slab is a remarkable isolation setup. The CD player is coupled firmly to the massive concrete block, and the compressed foam is unable to transfer any ground based vibrations to the massive concrete slab.

Oh, and it costs $10-$20. Low WAF, though. I use it under my rega planar 3 turntable with excellent results.

That should work really good w/ big isolation transformers (plus some hardwood boards & cones). I've used foam/bubble wrap with my power delivery/noise control gear successfully.