Turntable platforms

Granite has the inherent advantage of mass and stiffness and sounds great if it is isolated on springs as the top plate of the iso device. Granite cannot ring if it is isolated since the granite cannot be excited by floorborne vibration due to filter effect of mass and springs. airborne vibration cannot excite the granite either since any vibration on the top plate is dissipated by the isolation system. Granite or bluestone of sufficient thickness 2-3” can sound excellent if simply placed in very hard cones. If you’re worried that granite rings don’t strike it while listening to music. There’s not enough energy at it’s Fn to make it ring. The inherent stiffness of granite and bluestone slabs makes them very resistant to bending forces comprised in seismic vibration. 🔄

...a second shout-out for bone dry sand box.  In a jouncy room in a rental situation years back, full blown SOTA Star Sapphire rig (see posts) after the usual attempts..bladders, footers etc...a dead added plinth upon the sand, carefully leveled under the SOTA rig solved things.  A precise Marigo tuning dot application further addressed air borne concerns.  Hardware stores are open, good men and women...have at it! 
So, while reading in bed, my wife says, "Your clock is faster than mine."  ..slight pause..  "Yay!!!"        True story...we need our sports back.  More Peace and Patience.  Pin

Same thing with components as with turntable
4 curtain rings 
4 racquet balls 
place feet of components centered on the racquet balls 
vibration gone
done
or you can place granite in the racquet balls then your components
an engineer shows me this 30 years ago

 I use Minus K under my turntable and tube amps, they work well, no pumps and hoses to deal with, just science. I think they have a new model which is thinner in profile, yet does as good a job as the taller units such as I have. My Turntable is a Technics SP-10MK2 with an OMA plinth, it weights 200 pounds.

 I live in a wood framed building, wood suspended floor, it was impossible to play records before the Minus K because of the feedback issues. I tried granite + sandbox to no avail.

For cheap DIY dudes here’s one for the ages. Three Super Balls - the 3/4” size, not the bigger 1” balls - like they have in vending machines - and three Snapple bottle caps. The Super balls are great because they don’t store energy, they release it rapidly. That’s why they bounce so high.