Proper Ground for Tonearm and Turntable

How are you attempting to use the grounding wires currently? I suspect this has more to do with the tonearm grounding than the plinth grounding.  Typically your tonearm ground wire would attach to the phono pre. I would try only using a tonearm grounding wire first and disregard the plinth connection.  By attaching both to the same phono pre post you may be creating a loop...and a pop.

@three.. so presently not using the plinth ground at all. Just the TA1000 tonearm cable ground to the phonostage. Very weird because even with everything muted or even a different input selected on the amp I still hear a pop. Could it be static?

Right. Static. Sometimes just pulling a record out of the sleeve generates enough static the sleeve wants to stick and the record is attracting dust like a magnet. Get a ZeroStat. Meantime go to the store and buy Static Guard or whatever anti-static spray they have. Ordinary laundry spray works fine. I’ve never gotten the pop but use this all the time anyway because even when its not bad enough to pop it turns out there’s still enough to raise the noise level and add a little grain and glare. Spray over speaker cables and interconnects, hear the difference. If yours is bad enough you could try spraying the platter and table before putting a record on. Don’t spray directly over records, spray so it wafts just above and to the side. There’s a bunch of other more long term options (like ZeroStat) but this should get you by for now.

The tonearm is the only thing that should be grounded to the phono stage. If you must ground the plinth, it should be to your building ground (usually the cold water pipe coming in from the municipal water supply, only if it’s metallic) through a dedicated ground lead. If you use a well, the building ground electrode should be a long copper rod driven into the soil close to the foundation - check your local electrical code requirements for more info.