Turntable upgrade recommendations: SME vs AMG vs Technics vs other

@terry9 , air bearings are anything but silent. The air has to escape and can cause high frequency resonance. Plain bearings in oil done right are extremely quiet. The biggest issue is the thrust bearing which opposing magnets or a properly machined ball do just fine.

@rauliruegas , I have no idea why we argue so much. We both dislike unipivots and 12 inch arms all for the right reasons. Did you comment about the STST Motus 2 turntable yet. I am fascinated by it, a low torque DD turntable with a suspension that is user adjustable for various weight arms. The tonearm board is also clever. You drill the right size hole then you can rotate it to achieve a perfect spindle to pivot distance or change overhang.  It uses three leaf springs. I'm not sure this is a good idea as the lateral resonance point is going to be higher. If it gets into the tonearm resonance area you know what might happen.

@mijostyn 

True, a resonance can develop. But this is easily controlled with a massive platter, a well damped air supply, and tuned air pressure. There is no reason to think that magnetic suspension is quieter, but there is good reason to be suspicious of stray magnetic fields near a MC cartridge, especially if these are sufficient to levitate a high mass platter. 

A high mass platter is important to smooth the electronic jitter from cogging at the poles of an AC motor or the constant corrections of a DC motor controller.

IMO.  YMMV

@alexberger

I had a similar experience with a NA Spacedeck compared to an upscale NA, the Mentor.

Happened gain when upgraded the Mentor to full NA Dais specifications.

Happened again with the modern power supply.

Happened again with air bearing.

May not be the drive system.

Dear @mijostyn ​@terry9  :As air bearing high mass platter is not a " dream design ". Any body in movement develops internal vibrations/resonances as higher the mass as higher those kind of distortions.

Low torque DD TT as the other characteristics in the STST  " looks " fine but you can be sure that after you listen to you find out that exist some trade-offs, nothing is perfect in audio and especially with the analog alternative.

Why don't as MF about that " low torque " when he is in love with the high mass high torque SAT DD TT?

R.

@rauliruegas

"Any body in movement develops internal vibrations/resonances "

Almost true. But those resonances must be excited by vibration. Where does that energy come from? Not the air bearing - you are thinking of a conventional bearing, perhaps. The only other significant source of energy is the electronic jitter from a motor, and the worst are DD, then idler drive. And the more powerful the motor, the more energy to spill over into the platter and excite those resonances.