Vintage DD turntables. Are we living dangerously?


I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
128x128halcro
Hi Griff,
I've ordered a 5mm Achromat....but the 1200 which allows for the edge lip of the platter (named after the Technics 1200 because of the same problem).....
So....I'll see if there is still some improvement to be had...❓👀
For those of you that have platters that have a raised lip - it is a very easy job for a competent engineering workshop to remove the lip ( without upsetting the balance) which would enable you to run any platter mat, or alternately reduce the height of the lip so the record does not touch the aluminium platter.
Lew, re:
"I am surprised that one good oil would be noticeably superior to another good oil in a tt turning at most 45rpm", studying fluid mechanics would indicate that the toughest lubrication applications are slow speed as opposed to high speed where lubrication "wedge" can be easily generated by the fast moving parts.
That is why slow turning gears use high viscosity lubricants with extreme pressure additives to reduce wear and minute "welding" of the gear parts.
This is basic lubrication.
Viscosity is part of the equation. Another part is film strength and anti friction agents to support moving parts at high pressure.
The lubrication of a tiny ball bearing moving against a disc at slow speed is actually a tough application. It's like stilettos: The pressure of the bearing is fairly high (P=F/A) where A (area) is very small and F (force) is not insignificant and the slow 33 or 45 RPM is not sufficient to easily build a fluid film between the ball bearing tip and the disc.
A good lubricant can help since reducing friction in this point will benefit in less noise which transfers from the spindle to the platter.
Just my thoughts and personal experience.
Stop times are dictated by viscous shear (internal friction of the fluid layers) and asperity contact at the tip of the bearing. The higher the lubricant's film strength the less the asperity contact would be a factor and stop times will be dictated by viscous shear. That is why adding weight didn't really change our results with RP.