DIY TT

@vinylzone Thank You for the information and the knowledge of your exchanging the Plywood Board to the Substantial Piece of Maple Wood.

If a an additional piece of Acrylic is available of a suitable dimension, a option will be to consider a CLD Layer at this position in the structure, the doubling of the thickness will improve the structural property and it should be able to take the added weight of the Maple.

Acrylic in 8mm thickness has measured very favourably for damping and dissipation when assessed as Plinth Material, I am awaiting to see further measurements when it is used with a 0.8mm thick, double sided Teflon Tape.

As a First Tier in a Sub Plinth, the CLD design could prove to be quite a valuable choice.

 I use Cork Footers under a 30mm Thick Granite as my first Tier, and have one other not so commonly used material as a Tier sandwiched between Granite and Plinth with Two different design footers separating the sandwiched Tier.

@holmz The additional information and the variety of thoughts offered  from different end users, is always a welcome way to extend ones understanding and knowledge of products used. 

Being too insular in my experience is not going to bring inspiring discoveries. 

@vinylzone , nice work! I would like to make some suggestions. Hang the acrylic plinth from towers placed at the for corners. Depending on the mass distribution of the turntable you will probably have to use different rate springs at each corner the goal being for the plinth to bounce straight up and down at about two Hz. You can get an idea of the differential by putting a scale under each corner. Ten put the whole show under an acrylic dustcover. You can probably make the towers out of acrylic also. Could be a work of art. Look at and old Basis Debut or the Sota Millenium to get an idea. I don't want to be a PITA (yes I do) but you deserve a better arm.

@pindac 

I have tried glass, marble, and granite in the past, but not with this plinth.  I have found MDF to be preferable to either of those materials as a base shelf material.  However, I don't have a suitable sized piece of MDF right now to use as a base shelf.

@vinylzone We would get along mighty fine and dandy, with the inquisitive nature shared between us about materials used for structures to support TT's.

I am still trying to learn if the choices are just restricted to the choice of the materials, or additionally the environment the materials are used in to produce a structure.

I have taken other selections of materials to other homes, and the ones I thought were going to be the preferred ones by the assessors,  have been the least attractive selected on the day, to which I have been in agreement,  👨‍🎓👩‍🎓, more clever types might be able to help with that conundrum.

@mijostyn 

I don't need that kind of isolation.  No structure borne vibrations make it to the plinth.  The sub floor is a cement slab.  Springs of any sort do not provide any positive sonic benefit.  In any event, if I did need a suspension as you describe, I could always go back to my venerable Logic DM101 😀