Boy, Oh Boy! Towshend!

It was good to see a Foam used as Construction Layer for Isolation on the Symposium Products.
I have been using various foams with different compressive strengths for multiple years, these are the most impressive Materials I have used to date as a layer in a construction of materials to produce a support plinth.

I have a Pre Amp seatd directely onto a aerated highly compressible foam, to a point load the foam offers almost Zero Resistence to compressing.
This support lets the Pre' deliver a very clean and detailed presentation.
To date adding any other materials, to be used in combination with the Aerated Foam will show a smearing of the finest details.
If a air flow is not needed to enter the casing from the underside and the unlevel seating of device is not too off putting, this method is worth a investigation.   

@sokogear
I will look into Symposium for rack component isolation for sure. I just need to get my thoughts together on the Townshend isolators first. But I think I have.
Speaker bars with pods under my Mezzo Utopia's and isolation corners under my Sound Anchors rack(thanks tvad). That knocks vibrations to everything down to 3Hz. Just need individual component isolation next.

My left Rowland Model 12 monoblock amp behind my left Mezzo and near my sub is on its own Sound Anchors amp stand with spikes. The amp and the connected separate power supply are both made of solid, machined alumunum. 30 pounds each. Do they need isolation? If so, I could remove the stand spikes and put each stand leg bottom on a Pod? That would be half the price of 4 isolation corners. I don't think amps vibrate on their own, do they?
Isolation platters under the turntables I'm not sure what to do there. Because of the dimensions of my 2 t.t.'s and their dustcovers, they may be the last thing I do.

Thanks to everyone who help me coalesce my pathway. Almost there.

If you have the budget for it I think you will find Pods make a big difference under the amp. My Melody is on a 150lb slab of granite, which in turn is on BDR Cones, and it has BDR Round Things screwed into both sides of the chassis, and the whole thing is on a BDR Shelf. Pretty darn good I thought. Then I replaced one set of Cones with Nobsound. This was a lot better. Then I upgraded from Nobsound to Pods. This was hugely better! 

So even though already on a lot of really good vibration control the Pods still made a really nice improvement. 

Went through pretty much the same course of upgrades with my phono stage and motor controller, with pretty much the same results. They were all extensively tweaked out and in good shape yet Pods made them all even better.  

I don't think amps vibrate on their own, do they?

They do. Everything does.