Direct Drive vs. Idler Drive vs. Belt drive

Mikelavigne,

these are all airfloating designs but not using a real airbearing.
For a real airbearing you need a powerful compressor, it is 1m x 1m like the DUERR Technik. You need to put it into a separate room.

but these designs are very nice too!

best
E.

I personally think magnet floating designs like the Clearaudio and SOTA bearing are a more elegant solution for a thrust plate. As for which one is stiffer I have no idea. As Atmasphere implies the connection between the bearing and the tonearm base have to be absolutely rigid. With either the air "float" or magnet float designs there is an element of squish. So we have a trade off between bearing noise and wear vs squish and whatever that does to the reproduction of music. I would certainly think a compressor would wear out long before any top quality bearing and I have heard a number of top quality tables with standard bearings make essentially no noise that I could ascertain under normal use so to my way of thinking air bearings of any type are filigree. Opposing magnets on the other hand if stiff enough than why not?
I do find it interesting that this discussion has boiled down to derivations in belt drive designs.  

Mijostyn,
i guess you never heard an air bearing table, of which only two brands exist today. You do not have any noise from the compressor as it stays in a different room. Do you know about the advantage of air bearings towards other bearings? Of course it depends how far you are going with your system, most people do not like big compressors (maybe they never worked with a DUERR Technik).
Accepting a good design is ok as far as you do not like to reach „the moon“ 😀

Best
E.

This discussion hasn't "boiled down" to anything at all.  The subject at hand is always a function of who feels like posting at any given time of day or night.  My personal predilections are against excess complexity per se.  I don't want a compressor in my room OR in the next room OR in my system anywhere, not because an air bearing is not excellent but because I don't  want the complexity, the hoses, the moisture problems, the filters, etc.  And probably also because the turntables that employ air bearings are beyond my upper limits in what I am willing to spend.  There IS a point where cost is laughably high.

Even with magnetic levitation designs, there are quite different approaches.  The ClearAudio and Verdier, etc., designs float the platter, with a shaft only used to center the platter. 

Some designs use magnetic levitation to reduce the load on a conventional bearing.  This load reduction reduces wear and reduces the amount of noise generated by the bearing itself.  Hard contact, in this design,  is not designed to just prevent vertical movement, it is used to allow dissipation of any vibration imparted in the platter by the stylus tracking the grooves of the record.  The bearing itself is part of the path for dissipating this energy.