A while back I played around with Mappleshade brass isolators, their least expensive ones, and didn't really think they made much of a difference so I sold them. For my turntable I build a DIY platform using feet from an Audio Refinement CD player and it did make a slight difference in improving the tightness of the sound, although the turntable itself already does a decent job on its own.

I now have a different rack and was thinking of revisiting isolation devices for the preamp & other components. The mushy vibrapods are one option and brass spikes another. Now for a turntable, or even a CD player, I can see the point in that these have moving parts and spinning disks, but why would a preamp or amp need these? What is the physics behind this and does it really make a difference in sound? I've read the manufacturer's websites with claims of widenened soundstage and all that jazz, but frankly I didn't get that with the Mapleshade cones. Is this just snake oil? What is everyone else's experience with either of these?

One more point, the manufacturers rarely recommend different pods/cones for specific equipment, suggesting that they should be used for every component in my rack. Some even suggest putting them under my power center. This sounds a bit fishy to me and certainly would get expensive too. Any thoughts?