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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

Showing 3 responses by dan_ed

dan_ed
2,451 posts
 
Maybe you can get some ideas by taking a look at the pictures of the stand I just built based on one that Chris Brady used for his system. I used sandboxes and maple slab shelves but the thickest I went was 1". I don't think they need to be all that massive if they're sitting on sand. But if you decide not to use sand then that 4" slab of wood would be a good choice. I was asking the same question about the amount of sand before I built my stand and the consensus seemed to be that just an inch or two is probably enough. You will be surprised how much mass that is and how much dampening that will provide. I found that was very easy to level the shelves when floated on the sand just by tapping on the corner I wanted to lower. A great idea that I got from Brady's website was to use foam weather stripping around the edges to provide a finished look. What I discovered when putting things together was that this also sealed the edges so no sand could get out. I mean, I actually had to hold the weather stripping back to let the trapped air escape.

Even if you could get it you don't want a solid slab of wood. It would probably warp and check. That's why butcher block works so well, it is much more stable because the grain pattern of each piece glued together helps keep things dimensionally stable. (However, I have seen butcher block warp.) You can probably trust Chris and Timbernation to build it right. I think maple is excellant for shelves but again, I don't think it will affect the sound of the table so you can decide based on what you think looks the best.

Be careful with drawers, door, etc. You don't want to introduce any buzzes from vibrations. Nothing would depress you more than to get your new setup only to have it buzz on every 500Hz note.

IMO, I don't think you need to go crazy to get great sound from that turntable. I have never heard an HRX but I have to believe that it's suspension is well designed and implemented so it should not matter a great deal what table it is sitting on as long as it is sturdy.
dan_ed
2,451 posts
 
Gorgeous, Joe! Nice choice that copper and red coconut.
dan_ed
2,451 posts
 
Thanks for the compliment, Suttlaw. And thanks to Joe for getting that link to Chris's Tube Heaven up.

I completely agree with Salectric's comments about trial and error when it comes to shelves, stands and racks. I have had commercial products and they were fine, but they seem to always be expensive so if there is a short coming it really nags at me. I did some investigation before deciding on what to build and came to the conclusion that if I used the sandbox approach that I would gain most if not all of the improvements without having to look into other materials and products later. Some posters on the Asylum stated that they had used 3 to 5 inches of sand for boxes supporting heavy, high powered amplifiers and we all agreed that this was probably overkill for preamps and sources, so I settled on 1 to 2 inches and I think in practice that I can very close to an inch and a half.

Now on to the shelves. I like maple because it is fairly dense, cost effective, machines easily and the grain is nice and close so you can get a really smooth finish. Other choices may be birch, except it moves more with changes in humidity, cherry, sycamore (very pretty edge grain and when quatersawn), etc. I settled on making the two lower shelves 1 inch thick for heavier components and 3/4 inch for lighter stuff up high. I don't know why I made them thinner, but I do think that when the shelf is sittin on the sand it doesn't really matter much how thick is. My turntable sits on top but I really didn't notice much difference placing it there. I did hear an improvement when I moved the components to the sandboxes. Joe probably has some very good ideas on shelve material. I've seen the red coconut on his arm board and I can't wait to see the stand.

Again, I think your table will probably sound wonderful no matter what it sits on. The SDS may very well benefit from some dampening. There is a high probability that what I built is not the absolute best solution sonically, but I bet it is pretty close. IMO, this is one area where the law of dimishing returns really kicks in.

Oh, I made the shelves so that there is a 1/4" gap between the side of the shelve and the box. I then used 7/16 weather stripping, but the next thickness down would have worked just as well and would probably have been easier to slide in.
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