I want to thank everyone for your very thoughtful suggestions. However, I should have pointed out the problem I am experiencing is not from vibration(s), per se, but, rather, from acoustic feedback picked up by the TT cartridge at high spls. At least, this is what an audiophile tech told me after I explained the issue in detail The TT cartridge is so sensitive that I get a hum in the speakers at anything over a 50% gain, or so, on the MAC. Loud, I know, but sometimes I just like to play things loud. If this is, in fact, the issue then the only solution is to get the TT as far away from my speakers, as possible. So, imhififan, I'm inclined to think your suggestion of the Pangea amp stand just may be the solution. I hope so. Otherwise, I'll have to consider much more drastic steps (i.e. high-end TT interconnects or re-arranging the entire living/listening room). Thanks, again, all!