Vibration

I used to do it with my Wadia CD player. I imagine you are trying to get your components in between your speakers but you want them low so they don't interfere with imaging. If long as you use a good amp stand you should be OK. It really should be no different than putting the component on the lowest shelf on a rack.

"06-08-13: Zenblaster
What vibration or mechanical energy are you trying to isolate with a amp stand? Are they just for tube amps to reduce harmonics?
They do look cool sometimes."

You are trying to isolate vibration and/or mechanical energy.