My DIY Turntable
In the summer of 2010, I decided to build myself a turntable. My inspiration was the home-brewed table I'd seen and heard at the home of Robert May, my friend and frequent collaborator, who has one of the finest stereo systems I have ever heard. Robert's table is very different from this one, but mine is based on the same sort of principle: lots of mass, and good parts.
I actually haven't weighed the table, so I don't know quite how much it ended up weighing, but I've carried it around enough to know that it weighs a fair bit.
What you see of the base is constructed from Bubinga, which comes from the Guibourtia tree, an evergreen native to Africa and South America. Bubinga is often used in musical instruments and so seems a nice choice for a turntable. It's also nice that Guibourtia trees can be very large, so Bubinga comes in quite wide planks. I bought a piece 21" wide at my local lumber yard and had them plane it for me. They had to rip it to 19" to get it through their planer, but that was plenty wide enough to give me a solid piece for the top. As you can see in the pictures, the grain is really gorgeous.
The table is completely solid. The interior consists of four slabs of 3/4" MDF, glued together, with holes cut, of course, for the motor, bearing, and arm mounting. The Bubinga then forms a kind of shell around the MDF. I originally tried to mitre everything, to get nice square corners, but they weren't as square as I wanted, so I reconsidered and cut the corner pieces from scraps. I think they add quite a bit of visual interest to the table. The edges of the top were then finished with a router. If you look at the pictures, you can see where a piece broke off during routing on the left front edge. Bubinga tends to be full of gum holes and such, so this is a risk. In the end, though, I find the odd edge again adds interest to the piece.
The table is finished with a natural stain and a few coats of polyurethane.
The feet are old TipToes that I bought years ago for my VPI HW-19 Mk IV. The table then sits on a 1.5" slab of granite, which itself sits on what's left of an old Arcici Lead Balloon turntable stand.
I built the table so it would have interchangable armboards, much the way VPI's turntables do. There's a good-sized hole cut beneath where the armboard mounts, so as to accomodate different tonearms (should I change mine). Getting this to work properly was the hardest thing about building the table. I couldn't locate the mounting holes until after the table was assembled, but then drilling holes in the correct places in the armboard itself proved quite tricky. One nice aspect of this construction, though, is that the armboard can be made from a contrasting material. I made the original one from Poplar, mostly because it is cheap and, as I just said, I knew I was going to have problems. The current armboard, though, is made from Purpleheart, which is a gorgeous wood that is just a little bit purpler than the Bubinga itself and is plenty solid enough for this application.
As for the business parts, the platter and bearing are from a VPI TNT IV. The motor is the Origin Live DC motor, completely maxed out with the ultra controller, DC 200 motor, and upgrade transformer. For the belt, I'm currently using a piece of black string but am meaning to try some fishing line, too.
Tying the string so that it was the right length also proved to be a challenge. A little bit loose, and the table will not get up to speed; a little tight, and it puts too much pressure on the motor, which complains noisily. I eventually thought to take a scrap piece of wood, drive a nail at one end and then drive another at the length I thought I wanted, and at various 1/4" increments around that length. Then it was easy to tie "belts" at different lengths with some repeatable accuracy.
Total cost was about $2200: About $1300 for the motor; $750 for the platter and bearing (used); and $150 for lumber and milling. Plus several days of work. Of course, that doesn't include the tonearm, which is a Graham 2.2.
How does it sound? Absolutely fantastic, and miles beyond what it replaced. Much of this is probably due to the DC motor, but I'd like to think the massive base contributes something.