Glass Shelf under CD Player or not?

I don't think you can predict the outcome. When I had a Naim Fraim with glass shelves, the glass sounded far superior to Corian under my Linn. When I moved the Linn to a wall shelf, the glass sounded horrible and Corian sounded better than glass or even Neuance. Your ARC may or may not be sensitive to shelf materials. Just try the different mountings and see what you prefer.

I am apparently the odd man out on maple or any wood. I find it robs music of all pace. It may sound good but it is not conducive of realism in music reproduction.

I have many Mana stands which us glass on the top shelf. These stands which are now unavailable always had rave reviews. I found that the Neuance shelves in place of the glass were better, but Neuance is also out of business. Presently I use the Mana glass shelves again but they either have the Acapella isolation shelves or the Halcyonics active isolation stand on top of them thus negating any impact of them on the sound.

I did briefly have a Mapleshade maple base on top of one Mana glass shelf. I doubt if the glass had any impact on the sound of the Mapleshade. I did quickly remove the maple and put the cd player directly on the glass. I thought that much better but somewhat bright.

It would surprise me if you hear a difference with or without the glass in this case. Try it and see.

In general, though, glass is generally quite capable of transmitting vibrations at higher frequencies and I am not fond of it as a material that lends itself to isolating components from vibrations effectively compared to other materials, like wood.

What CD player are we talking about. Some CD players have good feet that are designed to be on a solid surface. If they are hard rubber feet, I would go try sorbethane feet to the chassis and use the glass directly on top of the maple to keep the sorbethane from possibly removing the finish on the maple. But as Cyclonicman and Tvad point out, you have the opportunity to AB or even C the possibilities.

I would consider Audiopoints with the Maple ( no Glass ) ..I am using a 2" thick Rock Maple slab with 1" high Audiopoints and it works fantastic....Vibrapods with Maple just blurred everything for me.......

I think it comes down to aesthetic preference. I doubt if blinded you would be able to tell the difference in sound.

Well you have the opportunity to try it both ways. Although this is a thick sheet of glass, I suspect that the CD player will sound better on top of the maple.

Glass is not a good choice.....