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
Now, if the isolation box is filled with sand or lead, does it really matter which wood you would choose?

I would imagine that MDF would work, and then just paint or veneer it.

In what order of magnitude is the different absorptive properties of the different woods discernable? especially in amps as one poster above mentioned?

If the wood resonates in a particular way, why not use MDF, isnt it why its used in speakers anyway?
Once I started getting posts to this thread, I held up on having the box built and did more reading. The wall sand and the isolation shelf eventually seemed the best way to go in my situation.
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.
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
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
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.
None of you has addressed the question of the air bladders, and whether they work.
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.
Suttlaw, my search for the best sounding stands and platforms for my equipment is still underway. I am using my Galibier on a 3/4" thick maple butcherblock shelf from Bed, Bath and Beyond, which is supported in the corners by the solid oak posts of a DIY stand. (Surprising as it may seem, I prefer that to the 3" thick platform from Timbernation.) My favorite mounting for my power amps is a solid walnut platform resting directly on the carpet. My preamps sound best on a short nesting table made of solid oak. I have not tried most of the (expensive) commercial offerings since I prefer to do things myself where possible. My next project will be a sandbox for the turntable where I can try different materials for the floating shelf.

My reason for posting here was not to say what is best, but rather to issue a caution about assuming that a thick maple BB platform will solve all of your problems.

My experiments to date lead me to two conclusions: First, different shelves and stands can sound dramatically different. Second, two people can reach opposite conclusions about which material sounds best. Ultimately, like most things in home audio, you have to try something yourself and reach your own conclusions.

Dave
Suttlaw,

I'll try to post a picture of what I'm in the process of finishing, and here is a link to Chris Brady's rack also:

Chris's Tube Haven

YMMV= Your Mileage May Vary

Mine is similar to Chris's, but uses red coconut palm, solid surface countertop material, Audiopoints, lead shot, walnut, copper sheet, and some other "secret" stuff. I know it sounds like a cluster&*%k, but wait till you see it.

Disclaimer: I build stuff!
Suttlaw: The Walker shelf and stand are very expensive. I posted the information more as a design example that as a purchase recommendation, even though I did purchase the one pictured for my Walker turntable. This is one of those things you'll have to ask Lloyd about directly. A telephone call works best; he's usually the one answering the phone.
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Many good comments. Thanks.

Rushton: how much does the rack cost and the top separate shelf cost? I couldn’t find the information on the website(s). Thank you for the picture. I checked the VPI website and they said they had a stand with more information later. I emailed them and Sheila, bless her heart, responded on a Sunday to tell me they had been selling the stand for some time but the webmaster had never updated. I’ll pass on the information about it when she gets back to me.

Salectric: Dave, thanks for you heads up, but I admit that your comments worry me. I thought that I had a good answer with a maple platform and now you’ve got me wondering again. I’ll start slow. What did you find that you did like under your components? Also, I hate to sound internet stupid, but what does YMMV stand for?

Psychicanimal: what is Carribean Moca…? And how does it sound?

Dan ed: My compliments on your DIY work. If I had any abilities like that… I checked the Teres website, but couldn’t find what you referred to. Where do I look? Did you use one or two inches of sand? How much space between the plinth and the sides of the box? Did you consider using a thicker plinth than one inch? Or something other than maple? I wouldn’t do doors or drawers, but I was thinking of one shelf about fifteen inches above the floor (so I could put LPs underneath) and with five inches space so I could put the SDS unit in it. What do up think?

Jphii: nice picture. Definitely considered Teres before the HRX.

Thanks everyone.
Salectric: Thanks, I agree; Lloyd does beautiful work. The 3.5" shelf sits on about 10-14 small lead discs (about 1/16th inch thick) spread across the surface of the top of the rack and located to match the mass of the turntable. The Walker turntable is extremely heavy and actually squeezes the lead somewhat flatter over time, so the result is a tight coupling between the shelf and the top of the rack.

Jphii: I've been frustrated for a long time at not being able to post a picture. I finally tried adding the HTML for an embedded image in an "edit your post" process immediately after making the initial post. It worked!
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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.
Rushton, The Prologue does look great! A couple questions come to mind: Is the 3.5" thick Prologue Shelf attached in any way, or is it just resting on the top shelf of the rack? And if just resting, is it resting directly on the shelf or are there spacers of some sort?

Suttlaw, I bought a 3" thick maple butcherblock shelf (18 x 24) from Timbernation and I was very pleased with the quality of his work and the fast service. However, for my tastes, the maple BB platform does not sound good. I have tried it under my Galibier turntable, my tube power amps and my tube line stages, and in all uses I observed the same characteristics: very smooth midrange and treble, BUT it is dead and lifeless and it lacks bass power and dynamics. Now I know that flies in the face of lots of reports to the contrary, and you can take my comments with a grain of salt. The only reason I am reporting my findings is to warn you to try the thick BB first in a limited way, such as a single shelf, before committing to a major stand or rack using multiple BB components. You may find it is just great or you may find, as I have, that the shelf doesn't have a home in your system. And yes I tried the usual types of shelf accessories: Mapleshade Isoblocks and brass cones, sorbothane spacers, brass spacers, maple cubes, etc. This is truly a case where YMMV.

Good luck!

Dave
Your VPI would probably work well on a stand and platform similar to the stand and platform Lloyd Walker manufactures on special order for his Proscenium Turntables. (Not from a cost perspective, but from a design perspective!)

There are two parts: a 3.5" thick rock maple butcher block shelf (the "Prologue Shelf", as Harry recommends for his VPI table) sitting on top of a high mass rack (the "Prologue Rack"). The rack is massively built using 1.5" butcher block shelves built with brass rods and nuts, brass cylinders filled with lead shot and mounted on 2" Valid Point feet. Here's a link to a picture and a description (scroll all the way to the bottom of page):
http://www.walkeraudio.com/proscenium_turntable.htm

It works well here, and has been received Jonathan Valin's praise and "Editor's Choice" award in TAS. So, it may be something to consider as a design to emulate for a high mass turntable.


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