Instead of paying $395 to Walker Audio I found a clear rounded quartz crystal and glued it to the front of my cartridge with a tiny dab of super glue. Of course I re-balanced the arm to account for the added mass. I've been playing records this way for about a month now.
No overtly obvious change, but things did indeed sound nice. So this weekend I decided to put it to the test. I pulled out 88 Basie Street, an album many of us are intimately familiar with for it's great dynamics, soundstaging, space, extension and great music.
(1) Sounded really nice with the crystal in place. Spacious, meaty, textured.
(2) I pulled off the crystal and re-balanced the arm. OK, so things definitely seem a bit flatter now. Less nuance. Less space. Less character. Absolutely a difference was heard.
(3) Glued the crystal back in place and re-balanced the arm again. Yup, there's that nuance, space and dimensionality.
Conclusion: so I guess this did make a difference to my ears, whether from actual RFI/EMI reduction or from just having added mass at the headshell or resonance dampening - I don't know. But I did hear it; subtle but there.