Designing a Plinth

Jimbo3, Cocobolo is a very dense wood. It has a density along with other woods like maple, rosewood, cherry, etc. These various densities are also very similar to MDF (medium density fiberboard). In most cases MDF is chosen for not only it's density, but also for it's ease of fabrication, not to even mention it's cost, especially relative to a solid "block" of Cocobolo. God forbid you accidentally "slip" when fabricating the Cocobolo.

You have probably also noticed many manufacturers choose to use an acrylic material for their platter. There is a method behind their madness. Acrylic, aka: Metacrylate, has a mechanical impedance characteristic that is very similar to vinyl. Your plinth will have a mechanical impedance also.

There are going to be areas in which you will need to "decouple" from vibration and other areas where you will need to "drain" vibrations. Especially with a non-suspended plinth.

Click on the websites below for a "primer" in DIY turnatables.

http://www.decdun.fsnet.co.uk/turntables.html#ttplinth

http://www.diyaudio.com/forums/showthread/t-18614.html

Well, the cost of cocobolo is not THAT bad. I wouldn't use a solid block either. Much easier to glue up pieces so you do not have to worry about wodd "movement" down the road. You can get enough to build a plinth for about a hunded bucks. Believe me, I know. Using acrylic is actually more expensive. the two I have going now will use about $200 worth of Staron each. Plus, the glue, glue gun, and tips are EXPENSIVE!

I actually think the wood is easier to work with.

Jimbo, don't know if you saw it or not, but here's the link to my TT project:

Joe's Teres

It's not that hard to do if you know what you are doing. By far the hardest part is making sure the boring for the bearing is correct. Every thing else is only limited by you imagination.

If you want any advice, email me. I'll be more than happy to share what I've learned.

Joe

I have been considering a variety of option for plinth making, myself. I would like to go the whole nine yards and do something very elaborate in terms of wood grain matching, inlays, etc., etc.

I am thinking of beginning, though, by making a plinth to replace or interchange with my stock Nottingham plinth. Fortunately for me, I have had a good deal of experience working with a large number of wood types. In addition to cocobolo (expensive because it is a hot item tight now), I am considering some woods that are beautiful, of different "colors", dense, and STABLE. A few on my short list include:

Mara (NOT Mora) - An absolutely GORGEOUS honey-colored wood, sometimes with striking dark streaks. Very dense and very stable.

Cebil - A wood that is very similar in looks to Black Cherry but is much denser, harder, and is very STABLE.

Quina - A reddish wood that can take the flavor of a very rich Honduran mahogany (with a more regular and wider graining) and can have very nice figuring. It is hard, dense, and STABLE. It is widely used in South America for cutting boards.

Argentine Lignum Vitae - Yes, a cousin to the more tropical cocobolo. However, this wood is generally much lighter - a sort of olive/green, not unlike some of the darker (not redder) oaks. Takes a mirror-like polish, too. It is a bit resinous, though, so an appropriate sealer is a must.

OK, I know that these woods would provide a very dense and stable plinth. Whether or not they are "musical" woods would be fun to determine. These woods are not overly expensive and someone might have a blast experimenting with them.

Keep in mind that a solid piece is not the way to go to insure stability and resonance "transfer" (if I am using that word correctly).