Mass and vibration cancelling on top of CD player?

Thanks Dave.

Why does it make a difference and what should be expected?

I've found at my modest listening levels my Lexicon RT 20(electrically well isolated and conditioned) does not vibrate from the bookshelf speakers I am using( and there is 16 feet from the speakers to my solid hi fi stand (wood); but, it does vibrate from its own turntable, more with some discs than others.I will try your suggestion tonight. PS. I once heard Wadia (581 I think)played through very nice horn loudspeakers in a very large (18'w x ~35' long by ~ 17 feet high) nicely treated (not overdamped) room. I was very impressed by the reproduction of classical music from the 60's ,on CDs, that I had previously only heard on vinyl. I was very engaged, satisfied and impressed with the musicality,detail and dimension of the sound. At about $6000 it was and still is out of my price range-so I envy you-well not exactly envy- but I'd probably trade you players in a flash!

Thanks Dave. Interesting but I think far from complete analysis. There are probably more technical articles worth reading-if one knew where to find them. I think I will open the player and observe/feel for points of vibration and possible improvements.
The value of having put the vibration absorbing/reducing mass on top of the cd player is very apparent on all music. I am very impressed and pleased. It has added significant enjoyment to my listening. Nice cost-free improvement for anyone. The clarity, depth, dynamics and transparency improvements are very satisfying.

ZD. I put a heavy book on a marble tile (on a piece of heavy cloth to protect the player)(no cones) on my Lexicon RT-20 and have been "very" pleasantly surprised. I was using a very "average" CD-- Portrait of John Williams (MK37791)-- as my test.
There had been a very minor degree of harshness in the higher treble notes that I had attributed to being the sound of his guitar (I should have known better-John's ear would probably be as sensitive as that the most ardent audiophile). With the added mass the harshness was gone! The CD all the more enjoyable. Without question this was due to "damping of the vibration to the player caused by the rotating disc" as there is absolutely zero vibration transmitted from the speakers to the player.
The added musicality on strings, as well as orchestral, is very much appreciated. I have exceptional separate ac isolation/conditioning for my pre, amp and the RT-20 and I probably am in a better position to evaluate this effect than most as I'm also using reference Spectral & MIT products. There is no question of the result-so I guess this confirms why the serious attention paid to ridgidity and mass among the high end players. I of course will now look to further avenues for sound improvement as I am not able to buy an Esoteric, Wadia, Spectral or other top CD or combo player at this time.
Any suggestions on my next experiment?

I don't understand why dead level is so important. It doesn't seem to matter to a gyroscope? I like the cork idea. Probably could serve more than 1 function.

Rhyno I'm not sure what you mean by "wall plates" and AC "distribution boxes". I agree on the Equitech's grounding information.

Thanks Rhyno.10/4