So Weird- No Stylus Contact Woofer Pumping with Hana ML and Elac PPA-2

As others have said, it could also be a magnet on the platter used to read and calibrate speed.

If it was a magnet on the platter, the problem would occur when the platter had no record or mat. If you look at the video, you’ll see that does not occur.

I think it’s a red herring, meaning something else is or was going on that neither we nor the OP have detected. Which is why I asked the OP to see if he can recreate the phenomenon by restoring the original conditions. It cannot be the platter per se because we see the pumping disappears when LP and mat are removed. Funk Firm mat contains no metal either. I’d bet the pumping has either directly to do with balanced mode or has nothing to do with what we see.

I certainly don’t blame the OP for not wanting to change back to XLRs just for my/our benefit.

Maybe I can pick up some cheap XLR to RCA adapters just for fun and see if it repeats.

I think the problem is stored energy in the vinyl and the mat- either separately or combined. 
 

I’m not sure if an earth grounded chassis would help. This TT is not earth grounded. The motor power is a 2 prong feed from a 120/100 volt step down transformer. The native power being Japanese 100v 60hz.

   Could be something is oscillating in balanced mode but why would it go away when you removed LP and mat? Neither of which can “store energy” for more than milliseconds. And it would be kinetic energy, not electrical.