Turntable

Bruce, Thanks for your expert input.  You wrote, "Also because TT bearings operate at low rpm bearing "failure" is a possibility and in this scenario reduced friction of the surfaces can be helpful."

Why does operation at low rpm's enhance (rather than diminish) the chance for "failure"?  Or maybe I do not understand how you are defining the word "failure".  Also, except in the case where the bearing is deliberately designed to increase drag on the motor so as to help maintain constant speed (e.g. the grease bearing in a Garrard 301), when would reduced friction NOT be helpful? Thanks.

I can't see the benefits in this application for a turntable at all. The best lubricant for this purpose, a turntable bearing, is per the manufacturers recommendation and care to use oil with zero additives. Many of these additives were/are designed to fill the void of scratches in engine blocks so piston rings can be even more efficient at their purpose. Inverted bearings, such as Michell's have a slight rifling to carry lubricant to the bearings fulcrum point then allowed to drain and replenish a flow back down the shaft. Minimizing that small rifling groove in any way , even the smallest amount when it see's a design as a flaw and attempts to fill it would most certainly reduce the designs effectiveness. It's , to me anyway, as wrong as those who tell others to replace bearings with far harder ceramic bearings in designs that are purposely made to make the bearing the wear point , not the shafts top. One requires the ball removed cleaned and replaced so it hits a new place of contact , the other may  require a whole new bearing from damaging the top of the shaft where the ball sits. As usual , the same tired argument made by want to be experts that the company only did it to make more profits is used.  Things are made at a cost without argument , however a product well established and with a specific design, then altered to defeat those specific's, is a poor specific users choice , in my humble view , for what its worth...…………..  

Oil well turntable bearings unlike for example a crankshaft bearing can't always generate the rpm necessary to assure enough pressure to prevent metal to metal contact .  Im not saying they don't work however, just contact is possible. Hi friction in a bearing in no way increases speed stability. Once warmed up and the viscosity changes it doesn't hurt it either. 

Thanks.  I guess the problem with low rpm would especially apply to an inverted bearing turntable. I am not sure that the braking effect of the grease bearing in an early Garrard 301 is totally analogous with friction but others refer to that constant drag as a way to stabilize the speed.

"Others" are wrong, LOL. 
Inverted bearings "work" better at low rpm in theory but have other disadvantages like higher friction. Lots of ways to good sound.