08-17-13: GeoffkaitGeoff, yes it seems conceivable to me that vibration absorption could be a key factor that is involved. And perhaps also its effects on tonearm effective mass, which of course can make a difference even when tracking force is adjusted to remain constant.
Al, interesting theory. It's also possible the crystal does no such thing and is simply a very efficient vibration absorber. If it were absorbing RFI/EMI I imagine the crystal would have to attract the offending electromagnetic fields like a magnet. No?
But note that the RFI/EMI/static theory is not mine. I quoted that explanation directly from the Walker Audio website. And note the "if in fact" wording at the beginning of my post.
I myself take no position on how it may work, or even if it works. But if it does work via the electrical means that are stated at the Walker Audio site, I believe that its effectiveness would vary considerably as a function of the various dependencies I cited.
Regards,
-- Al