I tried the Ayre blocks under the player I am using as a transport (the Meridian 508-24). It is on a different shelf, and I had previously put it on 4 Vibrapods (one underneath each of the feet shod by the manufacturer). This improved the bass. I was sober, which should satisfy some scientist somewhere as to the objectivity of my attempt.
Actually, it would be impractical to use these blocks (roughly the size of a domino, although about twice as thick) in any way other than that recommended. They are too thin to raise the equipment higher than the feet supplied by the manufacturer. They are too tall to put in end-wise, and still remain stable. I don't know about grain. I think they do a better job of coupling the chassis to the shelf than my old Vibrapods, and (judging from the results) they seem to eliminate vibrations better than the rubber. Why, I cannot say. It is not a miraculous transformation -- just a solid, audible improvement. In general, I suppose, it is a good thing to isolate components from the influences of vibrations, just as it is to isolate speakers (as far as possible) from wall interactions. At least, that has been my experience. If my rack were of a better design, perhaps the blocks would be superfluous. I'll never know, because I'm damned if I'll spend 2 grand on a new rack, the price of wine being what it is. I still have no idea why they actually make my power amp sound worse, while improving the transport and DAC performances. The transport makes sense, as there is a lot of physical whirling around inside, as mentioned earlier on this thread by...? (I forgot, and I apologize -- Mrlowry??). Now, I suppose I'll have to procure 3 more and try the preamp, which is currently sitting on Vibrapods. Cheers, all.