One turntable with two arms, or two turntables with one each - which would you prefer?

@pindac Have you tried slate? I have a 50mm Pennsylvania slate plinth under my rebuilt Garrard 401 with excellent results. interestingly, I tried granite and found it to sound quite poor.

I have a very nice Slab of 30mm Thick Slate, that I purchased which would produce Two Plinths.

Since my moving away from Massey Plinths, I have not been motivated to use it, or concern myself with learning how it works in comparison to Granite or Corian.

A Granite Plinth has not been experienced for quite some time, and this was with a Garrard 401. The PTP Solid Nine is readily available mounted on Corian.

I only use the PTP now to introduce others to the Idler Drive system and do the odd comparison to show how the TT drives can produce different sonic signatures.

I see the PTP as a very successful method to be used on an Idler Drive system, and in fairness, it is possibly the best use of the amalgamation of a modern design meeting design from an olden era.

I am at present excited about an upcoming experience I will be introduced to.

I see the PTP Design and the Kaneta Design as both coming from a similar line of thought, which is to have the engine decoupled from it usual mounting and attached to a material that is much more suitable for the purpose.

I have been instrumental in presenting this design to individuals who are with the Skill Set in both machining and electronics to produce this design for the SP10 MkII.        

The Kaneta Design produced from Densified Wood will be in place for myself to receive a demonstration very soon.

Additionally, it is to be produced to have a New Design Platter.

The Kaneta Design is flexible with Platters, which enables this version to be used with a variety of Platters, i.e, Original, Original Modified, New Design (Acetal with Increased Inertia and a Gunmetal Platter. 

The Design is to enable up to Three Tonearms mounted of which one can be a 12" Inch design.

This one has been a long time in the waiting to experience, it is a whole new territory of investigation, and I am chuffed at the thought of it now coming to fruit.

There is also a great opportunity be made available, to compare Tonearms against each other, as within my Group, there are a selection of sought after Branded Tonearms and Bespoke Produce Designed Arms.

Even better is that there are MC Cart's of the same Brand/Models with similar hours that can be donated to get the most from the new experiences to be encountered.   

I have built several TT plinths - here are my observations 

Panzerholz is not stable -it can warp and I would only use it in conjunction with another material that is dimensionally stable.

Granite - rings - no matter how thick.

Slate is ok, doesn't ring like granite due to its stratafied structure.

2 Materials that  I have had very good results with are

Engineered Stone ( high quality euro ) 95% quartz. Relatively easy to cut, you can source it cheaply from kitchen bench manufacturers ( offcuts ). Some have CNC facilities which makes it a doddle.

Compressed high density Bamboo ply. It is 50% more dense than Maple, and dimensionally very stable. I use this with my modified Garrard 301 and the result is exceptional. Even my mate with a Kuzma M/4point combo was gobsmacked when he heard my modded Garrard 301 with my compressed bamboo ply/birch ply hybrid plinth - medium mass, rigid, inert.

I find that Pz warps only when left unsealed. Is your experience otherwise? Thanks!

Modern Densified Woods by their very design are produced to be a material which is low in conductivity and selected for its properties where it is resilient to change when submerged in water, the Spec's show minimum uptake following 24 Hours Submergence.

Drawing on my whole experience of P'holz from the long-time owners, who steered myself toward the material, through to the most recent owners I am in contact with. Where across the Group, thicknesses up to 32mm are in use.

The purchase guidance given has been to buy Cross Grain Construction in B25 with a minimum thickness of 25mm.

There is absolutely nothing made known to me to over many years of knowing P'holz users to suggest a Cross Grain Lamination Structure in B25 of a minimum of 25mm Thickness is showing a tendency to warp.

I have my own supply of P'holz for nearly 18 months now.

A P'holz Plinth Produced, that is not in my possession at present, it is out on loan to an owner of the same model TT, the Plinth is produced for.

Additionally, I have a batch of boards that are cut to a dimension of 400mm x 500mm, I have just put a steel rule across these, and can report there is nothing seen to be considered as a concern. 

I am even familiar with a Standard Type Head shell design made from Cross Grain B25 P'holz that is now about six months old. I was handling a couple of the produced Items from a batch only a few weeks past. The Material to receive the Cart' is approx' 4-5mm in thickness, there certainly has not been any obvious signs of showing a deformation. 

I have no concerns for the above production specification for a P'holz material. 

There is another specification for P'holz, where it can be obtained with a Longitudinal Grain Structure. A board of this at a particular thickness might have a tendency to warp, but I am not familiar with boards created using this Grain Orientation on P'holz.