What isolation feet under your amp with great result?

+1 for the Machina Dynamica Springs. Have them under tubes amps and pre, and digital.
very very good.

https://www.youtube.com/watch?v=eKCWRCE9Vns

@rixthetrick - I received my springs yesterday and replaced the Stillpoints under my amps.  The springs I purchased look identical to the Machina Dynamica springs and cost me about $35 for 12 of them.

The amps now sit on 5 springs each, over purpose-designed SRA Ohio-Class XL+² platforms, which each sit on low profile, heavy Sound Anchor stands that are spiked through low-profile carpet into the concrete slab-on-grade floor.

I am glad I ordered extra springs since I realized the front ends of the amps are much heavier than the rear, due to the very large toroidal transformer in each.  Since I had extra, I was able to place a fifth spring directly under the holding bolt for the transformers and that was sufficient to level out the front and rear of the amplifier nicely.  The springs are not quite half-way to their fully compressed state resulting in plenty of play remaining up and down.

The compressed height of the springs is almost identical to the height of the Stillpoints so visually it looks great - I cannot even see the springs.  I need to post some upgraded system pictures since I realize I do not even have the new SMc Audio amps posted yet and they look pretty cool on the SRA stands.

Too soon to determine the sonic impact yet, but t if these sound good then I have 8 Stillpoint minis to use under other gear, or to sell.

I would like to try springs under my speakers which are on Sound Anchor Signature Stands and are currently spiked to the concrete.  I have a couple of challenges being that they are purposely tilted with the front being a little bit higher, plus the issue of the weight distribution being not exactly even.  The weight is about 170 pounds for each speaker/stand combination.  If I go with springs, I would want them to be very low profile.  I will give it some thought.  My other option for decoupling would be to try Herbie's Audio Lab Giant Threaded Stud Gliders at about $300 for 8 of them.  They would handle the tilt and provide a secure connection to the bottom of the Sound Anchor speaker stands.   Some here have reported good luck with those but I am a little concerned about either the Gliders or the springs sitting directly on carpet.  Maybe I should try hockey pucks first just to see what I think about the sound decoupled.

First go to a local granite store and pick up a thick piece to place on the shelf. For this size you should get it for free so just slip them a $20. Then place your absorption feet under the amp on the granite piece

@mitch2
I have given the springs interface to my concrete slab some thought also.
Because of the need to as much as possible directly couple with the concrete slab with my stands, I have just purchased some solid copper spikes to go under my stands which sit on the carpet at the moment.

You seem to get my point of not having a yielding support under the isolation springs, and yeah carpet is going to absorb energy. If you have not got a spiked base solution for under your springs, do go directly to carpet, there is low surface area, another gentleman in Agon informed me that after he removed pucks from under the springs (he purchased Townshend Audio Seismic Podiums) even with the feet directly on the carpet it improved.

I looked for solutions, and perhaps you could look also?
I found these https://isoacoustics.com/wp-content/uploads/2019/06/Carpet-discs.jpg
Something like that under your speaker springs would be ideal, and that's why isoacoustics made them. You could DIY with a metal disc and three spikes much the same. But I must admit these look pretty, and aren't too ridiculously priced at all.

On top of your amps now that you have isolation in place, the next move is to DIY version of http://www.audiopolitan.com/blog/eti-amg-toppers-review/
I know .... yet another thing...