what is the theory behind maple stands and racks?

Magfan, I used a 1.5" exotic granite slab under my TEAC Esoteric X-01 Ltd CDp for a while. . . In my opinion it hardened the sound. At the time I 'solved' the problem by interposing a $15 IKEA square stool top between the 2. But now the pretty granite has been relegated to end-table-top duties in the living room, and I have the CDp on top of a 50 year old 42"x22"x2" slab of solid african Mansogna wood. . . it does not seem to impart the system bizarre resonances. Some rack makers do use granite, but often not by itself. E.G. HRS does not use pure granite shelves. . . but uses granite as the top layer of composite shelves. G.

thanks for the interesting reponses. It appears that maple may be worth experimenting with. It is mysterious, or at least, not clear to me, how the coupling/draining vibration thing works, but that it can audibly improve things I have no doubt. There seems to be some combination of equipment coupling, vibration draining and isolation that works, but it appears to be difficult to predict how or why or what works. For example, I tried putting my amp (large tube amp, has large rubber=type feet) on spikes (i.e., instead of the "rubber" feet), on a white acrylic cutting board, sitting directly on the floor - poor result. Then tried the amp on the cutting board which was sitting on spikes, on the floor - excellent result (at least as good as a Billy Bags amp stand, which is, in a way, a similar combination of an inert shelf supported on steel coupled to the floor.)

Interesting - I had a similar result with solid state amp. Wooden platform had almost no impact on sound. Wooden blocks in place of amps rubber feet and placed on polyethylene board = little but slightly less appealing effect. Amp's rubber feet directly on poly board with the board on metal blocks on shelf - slightly better.

For all other applications (speakers, CDP, TT) I use wood - maple, ash and bamboo. The applications of these materials are driven more by cost, size available and aesthetics of a each piece, rather than focusing on the particular variety for given use. As long as the wood is fairly hard, it seems to work pretty well, again the thicker the better. Someday I may get around to doing an independent test of Mapleshade's claims for NA maple.

On a related note, I have tried Sorbothane dots directly under my gear, and used it to isolate shelves from stands and heavy wooden platforms from shelves. In these applications, I was not happy using the material to decouple equipment from whatever is directly supporting it as it seems to suck some of the life out of the sound. But I am happy using this material to decouple the platform from the shelf, or the shelf from the rack (can play system louder through room speakers before compression or distortion sets in).

This leads me to believe the purpose of the wooden platform is to drain INTERNALLY generated vibration away from your gear, while the purpose of an elastic material like Sorbothane is to decouple or isolate your gear from room vibrations originating from your speakers and transmitted to your gear through your rack. I say this because the benefits of the wooden platforms and anything you put between the platform and your TT or CDP (e.g. wood or metal blocks, cones, Sorbothane, etc.) are clearly apparent even when using headphones, and so must be interacting directly with the gear irrespective of room vibrations.

Finally, for your tube amp, I would think the platform material is a more critical factor than it seems to be for my SS rig. Since tube amps generally have big transformers, they can generate a significant amount of vibration on their own, and since the tubes can be affected by both internal and external vibration, I would also experiment with heavy wooden platforms and spikes/cones/Sorbothane as well for that application.

Shadorne, and they quite believe they are right!

Maple is easy to look at, reasonably stable, easy to source, easy to machine, and easy to finish. That's it, nothing more. Well, except that in some uses people believe it sounds better.

I built my stands using maple and walnut. Why? Because both woods are easy to look at, reasonably stable, easy to source, easy to machine, and easy to finish. ;-)

In my system I found that maple shelves (all of my shelves are on sandboxes) work ok under most of my components. It was horrible, IMO, under my turntable. So I tried granite. it was horrible in another way. I eventually wound up with 1/2" aluminum plate under my 'table, the table is spiked into the plate, and the plate is supported above the granite shelf with Stillpoints. I'm using rollerblocks under my source power supplies (that's where the tranny vibes are), and I let the stock rubber booties handle the CDP, preamp and phonostage chassis. So, in the end, I'm finding that no one shelf material works for me in all applications.

But if you notice I'm using several forms of vibration control. Some isolation, some damping, some coupling. It all just happens to be sitting on those maple and walnut stands.

Interesting thread.
Not sure how the density or hardness of wood types have on vibrational adsorbtion, but in the process of experimenting.
Per the Janka rating for density of hardwoods (steel ball thrown at material) I believe American cherry is 950, Oak 1250, Maple 1350, hardest being Brazilian Cherry 2750

I have some exotic hardwoods I will try under my primaluna 8 tube cd player, that should be revealing device to test.

Just made an entertainment center from 2 layers of 3/4" maple plywood with mdf in the middle, 2" thick. Seems to decouple well between components.
Also Picked up some squash and racketballs to add a poor mans floating layer on top of that by routing a cove bit pit to keep balls in place. Will let you know how it works.