Ideal material for wall mounted TT shelf

before i recommend the material bare in mind:
first of all the wall mount is never steady and as long as you're moving around your dwelling it shakes up and down even if you do not see it. that creates tension and apperently much heavier mass loads onto the material than whole structure weighs. so consider high school physics: lever, momentum and mass.
granite or marble wall mount stand together with your turntable will break your dry-wall even if you mount your structure into studs. for the metal studs i'd recommend removing a portion of other side dry wall and bolt-mount your structure through it. For any other than metal studs I'd recommend either reinforcing with metal or replacing wood studs by metal ones.

my personal preference is to plexi-glass 1&1/4"...2" thick. it's very easy to work with, very easy to set up, price efficient and great isolation qualities.

Hi Sunnyboy,
I cannot see the brass cantilevered supports on your System Page......however the wall hung shelf is definitely the right direction from your previous floor-mounted rack.
The wall mount should not move unless the wall itself is a stud frame supported directly on the floor joists?
If the wall is masonry or is independently supported from the floor......you're cooking with gas.
Assuming these brass cantilevered supports are correctly fixed into the masonry or timber studs......they will support the weight of granite, or marble together with the weight of your turntable (as you already know) :-)
Metal studs are the weakest structural elements imaginable. Their only function is to support plasterboard sheeting which gives the wall whatever solidity it achieves.
Metal studs are made of pressed metal barely 1mm thick and I wouldn't try supporting my lead-filled shooting stick on one of them?

Now to your question.....MDF is not...in itself....a poor material for the support of your turntable.
Remember that the table is effectively isolated (or de-coupled) from the shelf by the turntable's adjustable mounting cones.
I feel that a stone product like granite or marble is potentially worse in terms of their 'ringing' potential.
If you laminate both sides of the MDF with a veneer of laminate....you effectively create a stress-skin structure which is stiffer than the MDF alone.
If you really wish to throw money away.....you can try natural timber (butchers block) in a variety of species.
By creating a wall-mount for your turntable........you have effectively removed yourself from the sonic peculiarities of floor-mounted racks and shelving materials......and I'd be surprised if you couldn't already hear the differences compared to your old set-up?

Many thanks for your responses. This is a dedicated basement listening room with the TT mounted on a RCC wall that is part foundation of a 3 story building.
According to my architect friend as this is a load bearing wall there should be no problem supporting the TT platform.
Halcro
If you see the long shot of the system facing the gear you can spot the brass cantilevers under the TT shelf etc. You make an excellent point that the TW AC is already decoupled via its cone feet. The AC also rests on a HRS S1 iso platform. Changing the shelf material from MDF to say a compact plywood with a laminate may yield minimal sonic differences though I suspect the plywood is more rigid with lesser possibility of any warping etc
IMHO the switch from a floor stand to a wall mounted shelf took my vinyl system to another level
Cheers
Pradeep

A quick update. I replaced the MDF shelf with a plywood shelf consisting of 6 sheets bonded together. To look at its almost the same. Using my standard vinyl demo disc - Shelby Lynne "A little bit of loving" there is a clear tightening of notes. The drum thwack in the opening track is taut and with a certain crispness. It's premature to judge the set up on the one LP I have managed so far, but its a step in the right direction.
Many thanks to all who chimed in
Cheers
Pradeep