Why do turntables sound different?


Let's consider higher-end tables that all sound excellent. Same arm/cartridge and the rest of the chain. Turntable is a seemingly simple device but apparently not quite or not at all.
What do members of the 'scientific community' think?
inna
@has2be 

"I would suggest that quiet bearings would HAVE to be low in friction, period. The greater the friction the higher the noise."

Don't agree. I think that most would agree that the greater the friction the higher the energy to be dissipated. Energy can be dissipated by heat (microscopic motion) as well as by sound (macroscopic motion).
Just borrow the new Continuum Obsidian, you know, the one with the mag lev platter suspension, or Walker turntable, COPY it the best you can and don't worry about it. 
@terry9

I couldn’t disagree more. Your advocating in a turntable of all things that a higher level of friction in its bearing will not create more noise and vibration and the two are not related ? Sorry that’s ridiculous in my view. The whole idea of a bearing is to reduce friction between two surfaces. The better the bearing, the lower the friction and the quieter it spins, period. The best bearings for turntables have tighter tolerances in shaft and ball thus reduced friction AND quieter operation . Friction, that leads to vibration and noise and wear no matter how its dissipated between heat (leads to loss of lubrication , wear and premature failure),... and dissipated as sound, really, below a vibrating stylus that gets amplified about 800 times. Quiet and lower friction in this application go hand in hand. Do you actually suggest that higher friction in a turntable bearing won’t create and amplify vibrations, which is odd since reducing those energies from even being seems to be more a desire than fixing or ignoring its correlation. Most of the best turntables have bearings that certainly are both ruthlessly quiet AND as frictionless as possible. Slightest push and they spin effortlessly for far longer and with less need for the motor, also reducing noise. They reduce it at source , thus the platter and its design is even more effective.

Right. This is a very scientific approach - let the others do the job and steal the design. Some would argue, though, that the one closest to tape sound would be the one to copy. Continuum, I don't know, I heard that that's Technics not Walker.
By selecting a "thick" oil viscosity a high friction ( relatively speaking ) , quiet bearing is not only possible, it is commonplace. The usual thinking behind this design is that the bearing is more speed stable, which it is not . So, accepting that the logical extension is to build a bearing with the least friction as possible for the reasons noted above. The lowest friction bearings are air bearings, but the cost is complexity and potential pump noise.