@millercarbon
Great to have a thread for discussion on TT tweaks. Here are my questions and observations.
Matter of fact both the black and cocobolo platters were clearly superior. But the black was solid black like a hockey puck and cocobolo while beautiful hides the carbon fiber, they just do not look good together and so we had to pass. Lead shot spinning really looks the treat.I cant understand why you would start with an inferior sounding platter if you are looking to build the best sounding TT you can.
This would suggest that all your subsequent modifications and your conclusions as to their efficacy and impact on sound have been assessed with a platter that is not optimised, and could have led you to wrong conclusions.
Battery power supply. Same motor, only the power supply changes. Ability to run battery connected or disconnected from AC charger. So effect of RFI in AC is demonstrated and learned.
Why do you conclude it is about elimination of RFI, you are comparing a mains AC to to battery supply - I would have thought the stability of the mains supply affects the sound as much as any RFI. In fact a power supply does not need to be connected to the mains to be affected by RFI.
Chris used an inverted bearing design. Ours was an early version, with a stainless steel ball bearing riding on a teflon coated brass thrust plate.
Teflon or self lubricating polymer type materials are a cheaper alternative to a properly desgned bearing. Teflon thrustpads wear out - quite rapidly actually. Have you thought about try lignin vitae for example. I see you replaced it with silicon carbide and tungsten thrustpad. You might be interested to know the Brinkman uses a plastic thrust pad - very disappointing.
If you want to look at some of the best TT's on the planet, check out TechDas, Clearaudio, Brinkman and if you want to go cheaper, check out Kronos and VPI.
Well the Brinkman uses a plastic bearing, the Clearaudio Statement cant hold speed accurately - some of them are not a great as you might think. There are a lot of shiny balls in audio.
One of the best ways ( and least expensive ) to improve your system as you have done is to read up, question everything and most importantly think !