Improving a stone rack

I have a very dead/dense/heavy pair of hand crafted steel framed stands (filled with sand/shot 50/50). The top has 1" thick non-Gabbro granite shelves/plates (polished and beveled) mounted on silicone footers. I have no problems with various rubber soled equipment (EAR pre-amps, Zesto SUTs, a pre-amp that had thin aluminum base using Stillpoint SS footers, etc). I do have a problem with an EAR 324 phono pre which sounds best with a buckwheat pillow under it. My VPI VI turntable always sat on a 1.25" thick HDF board on top of a Townshend Seismic Sink (terrible footers on the table).

Below, I replaced the thick tempered glass shelves with silicone bumpers with 1.25" HDF mounted on Blu-Tac which appears to completely deaden the already dense wood. Maple/butcherblock would have been an alternative.

I have a tempered glass rack that does emphasize the highs and makes everything sound a bit "sterile" and cold.

I solved the problem by having my electronics on some bamboo cutting boards (Ikea Aptitlig) which themselves rest on 4 Moongel pads (the stuff used by drummers to dampen their drums). Works a treat and I don't hear the mushiness normally associated with soft stuff such as sorbothane.

After reading a lot of posts on Nobsound springs, I have decided to give them a try, and have ordered three sets of four. @noromance and @millercarbon helped me make up my mind. Basically I warmed up to the idea that you need a vibration-free stand AND vibration devices. So, we'll see. It will take some time before they arrive.

My speakers are sitting on the actual Duluth Gabbro Complex, they sound very good. 

@rolox wrote "I have a tempered glass rack that does emphasize the highs and makes everything sound a bit "sterile" and cold." I understand what you mean! Springs (like Nobsound) most probably won’t solve all of that, but hopefully, help reduce it. It is one of my three strategies: damping component vibes (better feet), damping reflective surfaces (shelves and back wall), and damping the shelf bottoms with absorbant mats. I realize I have an Ikea Apetitlig in our kitchen, and should try it.

@fleschler - my VPI hw19 experience was the same. It needed good feet and even a sand box platform. And the springs needed very careful ’just so’ tuning. Interesting that your phono pre is the one where you noted problems. It is the most sensitive component in my rack also.