Best isolation device

I use the ISODES polymer feet with my gear(also have a bello rack). If I am not mistaken, the ISONodes were a recommended tweak by stereotimes were well receiive by various reviewers. The manufacture of the product is Brightstar

Good luck

Harmonic Resolution Systems (HRS) M3. By far the best I have heard. I have one under my preap and one under my digital source. Not cheap but occ a used one comes up on AG

Read the reviews:
http://www.avisolation.com/reviews.html

If you must stay with glass shelving you could replace it with safety glass, as in windshield glass. It's a laminate which should help dampening. Acrylic would be an even better replacement...

My experience has led me to the conclusion that there is no such thing as "the best" isolation device that works well in all systems in all situations. There are just too many variables involved to extrapolate the results from one system to all others. Isolation feet that work well under a turntable on a glass shelf in a rack sitting on a cement basement slab may not sound good at all under a CD player on an MDF shelf in a rack on a joisted floor three flights up in a 150 year old house. Unfortunately there's no substitute for trial and error.

Bob_bundus, how do glass doors affect resonant glare?

MANA uses glass shelves to great effect. I would recommend thick (at least 1/4") tempered glass. Like anything in audio, try it, you might like it.