Vintage DD turntables. Are we living dangerously?

I finally do understand why you are concerned about the mechanical vibration of your transformer. A good platter mat can isolate the LP from such low level disturbance. Also, sometimes you can make mechanical transformer hum go away by judicious tightening of the bolts that hold the transformer laminations in place. You have to do this very carefully (don't just crank down on them with all your might) and symmetrically (tighten all of the usual four bolts a little at a time and see at each step whether the hum is reduced or finally gone).

Can you hear the hum with the bell of your stethoscope placed against the platter mat, where the LP sits? If not, no worries.

"Mercury" in flu vaccine
Sorry this is way OT, but it is one of my pet peeves.
There never ever was any "mercury" in any vaccine. In some vaccines, like inactivated influenza virus vaccine, there is and was thimerosal. Thimerosal is not free mercury. Thimerosal is an organic (carbon) compound which contains one atom of mercury per molecule in covalent linkage. The thimerosal is there to reduce the risk of bacterial contamination of the vial; it is basically an anti-septic. About 15 years ago, someone added up the amounts of all the thimerosal then contained in all childhood vaccines and discovered that it could exceed the safety limits for an infant. There was a furor in the US, and thimerosal was removed from all childhood vaccines very shortly thereafter. Currently, there is no thimerosal in influenza or any other vaccines given to children. There is still some thimerosal in multi-dose vials of flu vaccine(but not single dose vials) intended for adult use. Thimerosal intoxication is not linked to Alzheimer's or Parkinson's disease, except by hysterics, and anyway was never at issue with vaccines. The amount of thimerosal in vaccines where still in use in rare cases is (and always was) way way below even theoretically toxic amounts for adults and even for infants, except for the potential cumulative dose to infants as of about 1995, as noted. (No thimerosal now in any childhood vaccine at this time, to repeat.) Naturally, the anti-vaccine folks have seized upon this and other red-herring issues, as a reason for people not to get vaccinated. The long term consequences of not being vaccinated are negative for all of us (because of the loss of herd immunity against certain diseases). This is why we lately have outbreaks of polio, mumps, and measles in the developed world. People die from those diseases, sometimes children.

My profound apologies.
That blather about thimerosal was in response to a post on another thread. As the late great Gilda Radnor might have said in the guise of her TV character, Emily LaTella, "Never mind."

Wow, what a great thread. However, no mention so far that Goldmund and Micro-Seiki
used JVC core motors.
Anyone care to elaborate on this?

Wahwah, I recently found out that the Luxman PD-444 (made by Micro-Seiki) used a slotless/coreless motor. So MS apparently used both?

Lewm, I thought some more about it and tried a new test: I lowered the stylus directly on the Achromat platter mat, at zero rpm of course, then I raised the volume to twice my listening level and I couldn't hear the transformer humming in my speakers. So, 'if it ain't broke, don't fix it' seems to hold here. I am leaving well enough alone.
Gary