Designing VPI HRX turntable stand long


I just brought a VPI TNT HRX turntable home, and it won’t fit on anything I have. I thought I would get a 4” maple butcherblock platform (as recommended by Harry Weisfeld, designer, said one post) locally and be able to set up right away on top of one of my stands. Unfortunately, I found I could only order one of these through local lumber yards. Since I was going to have to wait anyway, I looked online for butcherblock and found Timbernation.com (Chris). Scrolling through the products, I saw a sandbox he had made for a customer’s amp, which reminded me of the Big Rock sandbox affair I have used with good results in the past. Hmm, put legs on it and I have a turntable stand at a reasonable cost. I emailed Chris last night and he got back to me today (Sunday). His website indicates that he can build whatever I want, so I am looking for some input into the design.

The physical information:
-the table has a footprint of 25x29
-the chassis (all metal prototype, not the acrylic/metal sandwich current production model) weights 70 lbs.
-the motor/flywheel assembly weighs 34 lbs. and fits inside the footprint
-the vinyl platter weights 17 pounds without perimeter ring and is 13.5” in diameter with the ring
-the metal platter (the original platter) weighs 27 lbs and is 11.5” in diameter
-the outboard SDS is 19x9x4 and is relatively light

Issues:

1. materials: what wood would sound best (maple, cherry, walnut, etc.), how should it be assembled (butcher-block or laid out flat; Chris’ website says there is no such thing as a single block of wood of requisite size), and how thick should it be? I don’t imagine the manner in which the wood is finished will make a difference.

2. sand: how deep should the sand be underneath the wood slab and should the sand go up the sides between the slab and the box it sits in? If not, what should go between the slab and the box?

3. dimensions:
a. the slab has to be at least 25x29, of course, but at least a 1” border around the footprint would make sense, making the slab 27x31;
b. I was thinking the slab should be level with the sandbox, so if the slab is 4” thick and I use 1” of sand, the box would have to be 5” deep;
c. How much space between the slab and the box, one inch, ½ inch?
d. How tall should the stand be? I’m used to a turntable at eyelevel on a wall platform, but that is not going to happen. Ergonomically, 25” seems good for standing upright over the table and changing records, but making it higher would make it even better. However, I don’t want to compromise stability for a couple of extra inches.
e. How thick should the sides and bottom of the box be, the legs and any shelves? (Chris would probably know.)

4. shelves:
a. first, whether to have them at all. Will they affect stability (maybe improving it by cross bracing)? Will they affect sound (by adding vibration carrying elements)?
b. How many?
c. Where placed?
d. It would be nice to have all my turntable paraphernalia in one place, so storage use if shelves are employed: SDS, 2d platter, dustcover (maybe hang from side of stand on pegs?), peripheral ring, center clamps (2 – original screw on and later weight only), setup equipment, stylus force gauge, demagnetizer, stylus cleaners, brushes, etc., the playing LP cover/inner sleeve/outer jacket, LPs in current rotation.

5. miscellaneous:
a. leveling the table with adjustable feet?
b. ???

I would appreciate any input before I finalize the design with Chris.
suttlaw
I saw the ULTIMATE turntable stand over the weekend. I was at Rensellear University attending parents weekend. I visited the the physics department where a graduate student was demonstrating and explaining some of his work with a scanning tunnelling electron microscope. These scopes are used to measure the flatness of materials to within the thickness of one atom. Of course absolute stability is critical to these instruments since a speck of dust falling on the surface is like an earthquake at the atomic level. They are mounted on huge slabs of marble with pneumatic suspensions. These suspensions might be prohibitably expensive but I wonder if you might rig up something comparable with something more readily available like automotive shock absorbers etc.
Hi Jyprez,

It is important to remember that the electron miscroscope is not subject to high volume SPLs of music as it is being used the way our audio components are. The main design objective of the granite/pneumatic mount is to address floor-borne vibration. Because the granite rings (even thick pieces), if there were high volumes of music present in the room the granite would impart that ringing into whatever is set upon it. The miscroscope also does not have multiple motors operating inside of it the way a CD/DVD player does so the design objective of the granite/pneumtic mount also does not include addressing internally generated vibration.

Best,

Barry Kohan
Just wanted to show what the top shelf I'm about done with looks like. I have not put the lead in yet, so I can carry it home. It weighs over 100#.



Nice end grain!



Lead goes in the cavities. The copper sheet is bonded to Staron, and there is a Staron piece in the bottom. There is Dynamat that goes between the Staron & the wood.



I'll let you know how it sounds.

Joe
FWIW, I finall got a Black Diamond Racing The Source Shelf for the TNT-HRX and put it up on a wall shelf with BDR cones between the wall shelf and the Source.