FWIW - Different ground locations can have different results. When I first grounded my platter spindle (VPI TNT/Classics platter), my first ground attempt was to the phono-preamp ground connection. This was not successful - record playback was still noisy. I then tried a ground post that is on the balanced power transformer (BPT) that supplies power to my system - this was not successful. I tried grounding it to a 120VAC outlet different than the one supplying the BPT - that was not successful. I now have the ground wire (1/4" tin plated copper braid) attached to the 120VAC outlet ground with a banana-plug (lug via the cover plate attachment screws is an option) that supplies power to the BTP. This follows the basic wisdom to ground back to the source to minimize circulating ground currents/voltages; and it may be more than just grounding to drain away static, there 'may' be other electrical noise in-play.
Just some personal experience.
Just some personal experience.