Mass and vibration cancelling on top of CD player?

dave, your understanding of the holy trinity (vibrations, AC & room) is impressive; if i had to boil down how to build a good sounding rig, you nailed it.

appreciate your thoughts on vibration control. FWIW, i got great results with AC by using the wall plates and dedicated vibration control of AC distribution boxes (critical!), and the addition of a technical ground as described on equitech's website took my resolution over the top. YMMV, but thought you'd appreciate these findings.
best

look at products by oyaide & furutech that are simply wall mounting plates for an AC outlet (which also must be upgraded to an audiophile-grade duplex on a dedicated line, to do it right). and, if you have a power conditioner / distribution box, you must address vibrations of it, likely before worrying about the preamp IME.