Where to use Isolation devices

07-27-11: Theaudiotweak
...Resonant energy is still trapped and slow to leave it really needs to be provided a grounding pathway.

... which may explain why my turntable sound improved so much when I placed my coned and footer'd turntable on top of a massive 30+ lb. butcher block cutting board. In fact, I'd been using a 10-lb. cutting board and the swap to a much more massive one made a dramatic improvement in lowering the noise floor and bringing out inner detail, dynamics everywhere, and truth of timbre.

The amount of sink mass needed is probably proportional to the amount of vibration in the device, and of course turntables have the most.

07-29-11: Theaudiotweak
John

You now need to ground/terminate the 30 lb. slab it has an even greater reserve to fill of unwanted resonance. It can sound even better yet. ...

I'm currently using the butcher block as an isolation platform. My turntable is a Technics SL1210 M5G. I replaced the stock feet with M6 threaded brass cones which have detachable points. When the points are removed the bottom of the cone presents a concave surface. I place the cone's concave surface on the steel ball of the Vibrapod Cone, which then rests on a Vibrapod Isolator. This assembly then rests on the 15"x20"x3.5" rock maple end grain butcher block, which is isolated from below by a pair of 3"x20" silicone gel wristpads designed for computer keyboards. This assembly rests on the top shelf of my rather budget but rigid equipment rack. I isolated the butcher block from below as well because the turntable's pickup could send finger taps on the shelf out to the speakers. This is much reduced now.

You can see the whole assembly here.

07-31-11: Inna
You could experiment with something different under your maple platform, I mean cones or perhaps Mapleshade isoblocks. I certainly would.

Well, I do have a drawer full of Vibrapod Isolators I could try in lieu of the silicone gel pads. Looking at those two options from an isolation standpoint, the gel pads look like they have far more damping mass to absorb vibrations, though.

I first picked up the gel pad tip from a DJ who used them under his Technics SL1200s in dance clubs. He said it made a huge difference in how far he could turn up the volume (and bass) without getting feedback. They're very effective at that.