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

Jphii, I just had to tell you, absolutely beautiful work. How does it sound? I also, am capable of creating a turntable of this quality.

My tool of choice? A checkbook.

My compliments Joe.

Jimbo, I have been sitting back with great interest reading this thread as it has progressed. There have been some great contributions. I was impressed by the workmanship entailed in Jphii's turntable.

Last evening, I stumbled across the website I have provided below. I have never seen such a complete and diverse offering in terms of wood selections and pricing. Maybe that it is simply due to my lack of knowledge and exposure in this subject. Although, I found the "Musical Grade Hardwoods" section particularly interesting.

Hopefully it will provide some additional info for everyone involved. Ed.

http://westpennhardwoods.com/default.htm

Jim, 4/4 designates the material thickness. 4/4 would 1" thick, 8/4 would be 2" thick. 5/4 for example would be 1 1/4" thick. BUT, (just to confuse matters) this is not always the actual thickness.

The site offers "dimensional hardwood lumber". A 1"x4" is actually 3/4" x 3 1/2". Although, I don't know if that is the case with lumber of the "non dimensional" type. You would need to consult with the other contributors to this thread, as I have no expertise in this subject.

Jphii, I also found that highly unusual. But again, I won't pretend to know anything about this stuff, cause I don't. From the theoretical mechanical/electrical design/engineering aspect, I could hold my own. But when it comes to the actual woods?

I subscribe to the old theory:

"Better to be silent and thought the fool, than to open the mouth and remove all doubt".

Something like that, but I'm sure you understand what I'm attempting to say.

I was actually trying to find a website that provided resonance/excitation frequencies, and vibration dissipation characteristics of wood (I have no life), but with no success. Does anyone know of such a site?