What isolation feet under your amp with great result?

Without a doubt, Symposium Acoustics ROLLER Block HDSE.  When I first purchased them, I expected some improvement, but when I installed them I got huge Improvements in air, soundstage (both width and depth), and clarity.  It literally was one of the best improvements I’ve experienced.  No change in tonality.  Everything is just so open, with much better focus.  I highly recommend these!  You will not be disappointed!!!

@lowrider57  I've replaced my Herbies with DH Cones. They are ceramic and sit under the component with the point facing down onto a hardwood platform such as maple. They do not colour the sound.

I agree with the ceramic cones and hardwood platforms+++

I am using tempered brass cones that I had machined many years ago and a few of Michael Green's (fairly cheep but nicely made) brass cones. I have them point down into a solid piece of 19"x15"x2" black walnut board, using a thin disc of suede leather between the bottom of the component and the base end of the cone. Between the heavy glass shelves of my three shelf rack and the black walnut planks, I have a heavy rubber/felt isolation pad at each corner. 

As set up, I'm most happy with the neutral, open, clean and detailed sound I'm getting from my system and have no interest in spending thousands of dollars on someones miracle products that I know will give me net 0 improvement over what I have.

Happy listening......Jim 

What about those cork squares in a lined rubber sandwich design? I have them under my Plinius pre and amp. Inch and a half thick, 2.5" square. Put them under the component, not the feet. They seem to provide isolation and detail. They were the rage coupla years ago. Anyone comment on their experience with these? Not much dosh ($). 

@lowrider57  I tried Myrtle wood blocks and there was a major improvement over Herbies, faster attack, open soundstage, but the highs became harsh. Looking for an inexpensive tweak. 

Before spending more money, try putting a thin piece of sued leather, just slightly larger than the block, between the bottom of the Myrtle wood blocks and your component. It will not hinder the performance of the blocks but will eliminate any micro vibrations that can build between the component and the coupler, which sometimes shows up as a sibilance in the highs.

It's a cheep experiment, I think will solve your problem without negating your otherwise good results.....Jim