Just a question on the slate for my clarification. Are you finding slate sounds better than granite? I am assuming you have compared and do find it better. They are both natural materials but granite is harder with more structural integrity. So what is it about the softness of slate that appeals sonically to you?
That's a good question, and one that in the little tiny world of turntable DIY efforts has caused more angry posts than just about anything else. On Lenco Heaven it once rivalled the Tube vs. Solid State flame wars on Audiogon (and elsewhere).
So what follows is my pseudo-science-based opinion:
I never tried granite as a plinth as 1) it rings like a bell; 2) it's hard to work; 3) I really don't like the way it looks (and as an architect, I've seen a lot of granite. Sorry, just don't like it, from Absolute Black to Baby-Sh!t spotted tan...not my thing).
So slate? Well, it acts differently than granite. As an anisotrophic material (referring to an object or substance having a physical property that has a different value when measured in different directions. A simple example is wood, which is stronger along the grain than across it), it provides a route for vibrations to move easily only in one direction, which is parallel to the plinth. This is because being formed from sedimentary processes then metamorphized and folded, it is made up of layers that cleave along a weak line of mica deposits (this is what makes harder slates excellent for roof tiles: it splits along one axis into workable shingles), and as vibrations like to travel along the path of least resistance, they move along the cleavage lines but not through it. well, not as much...Anyway, we can't know which direction the vibrations are coming from, whether they are from the motor, the cartridge, air-born, or foot fall. But I like the idea (whether it's real science or my own personal BS) that i can mitigate the vertical movement in the plinth. Horizontal? well i think i'd like to try a Herzan or something like it. Not all slate is the same. Some is very hard (really good for roofs and flooring) and some is soft (good for plinths). Pennsylvania Slate is soft, as is the Italian slate that Stacor uses in their racks.
Now after writing all that, I looked up the spelling of Stacor and found this, which is more succinct than my rambling. But I spent time writing it, so I won't erase it! LOL.
STACORE: “
Slate – a natural metamorphic stone with a fine foliated structure. The main building material of our anti-vibration platforms. It has unique damping characteristics due to a combination of high mass, softness, and a fine layered structure. The layered structure, unlike e.g. crystalline structure of granite, efficiently dissipates vibrational energy by the layer-to-layer friction."
So that's one part...the other is that it is beautiful, and that plays not a small part in the overall experience of enjoying music i love...Does it sound "better" than other materials? Not sure. The Slate Lenco is truly spectacular as a full front end, but so is the TD 124 and its wood plinth. And what i most like is that i don't ever find myself thinking about the "sound" of any part of the front end except the cartridge...and that's another problem all its own.