Its OK that the phono section isn’t grounded to the wall. What is important is that the ground of the ’table is the same as that of the phono section.
IME the platter pad can have a big effect on static. I’ve never used a delrin platter though.
Thanks for the info, @atmasphere - I went ahead and connected it that way.
So certainly, this case appears to be a complex problem with a lot of variables. I got the Hudson Hifi arm brush for static dissipation - easy to use, and a nice product for cheap. I’ve been very careful to eliminate any sources of static - and yet the problem still persists (on average once every several records or so). So I think we can eliminate static discharge itself being the primary factor. The common point here is the preamp (as Ralph surmised earlier).
So I dug up my Rogue Athena preamp and subbed it in. This is a more traditional design with analog attenuator up front (motorized stepped attenuator), and it also uses Jensen line transformers for I/O conversions (SE to balanced). I swear the surface noise & pops/ticks seem a bit quieter, and no "mega POP" has occurred yet. If this holds, then perhaps it points to the Ref 6’s digital attenuation not fully blocking the circuitry from overload conditions in all cases (I’m no circuits engineer, just stretching here)? I didn’t face the issue with this same Ref preamp in my main rig - but yeah there are a lot of variables at play - for one, the main rig speakers are 6dB more efficient. Thinking back I’ve certainly noticed that the Ref preamps in general (I’ve had two now) do seem to "enhance" the record surface noise a bit versus traditional attenuator-based designs like VAC. Other than that, they sound absolutely specular with vinyl...but I just can’t keep subjecting my tweeters to this when Tannoy doesn’t supply the parts anymore...catch 22 :-/
** Again thinking back a few years, I remember a humble little system I put together with NAD C368 integrated used as the preamp (digital volume control) that also faced the mega POPs issue with vinyl. Is this a general issue of using digital volume controls with vinyl for loud playback?
So I’ll enjoy the Athena preamp for a while, hopefully get used to its sound (some pros, some cons versus the Ref 6), hopefully not experience a mega-POP again, and report back :)