Has anyone seen this? A really beautiful turntable

Mijostyn, "The background noise on even the best pressing is a lot higher than any reasonable modern belt driven turntable so in reality a solution in search of a problem."

Do you think that bearing noise is irrelevant? If so, I assure you that it is not. Just listen to an air bearing TT with air in all three dimensions.

As Glen said, what about stability? What fixes the record with respect to the stylus? Does the platter wobble when the stylus is dropped? Horizontally? Vertically? Got to suspect it does, at least somewhat, and the effect is audible.

Mijostyn, from your posting about computer files I infer that you have not experimented much with the sound of electronic components. It is highly rewarding, and the physics is pretty much understood.

In general, lower dielectric absorption is better (take-away: teflon or styrene film and foil caps). Faster devices are better (hyperfred diodes, high ft transistors). Etc. A whole new dimension ! Enjoy ! 

@lewm

Good question. Experiment was as follows.

Began with a TT which is famous for the quality of its bearing: Nottingham Analogue, one of the last Mentors, with the Dais bearing (their $10,000 TT). I played this TT for years and years, before:

Decided to build my own DIY air bearing TT. Inspired by the NA design of massive cast iron sub-platter with 1" of graphite sur-platter, I bought a large soft extruded iron billet and had it machined into a 45kg sub-platter. I specified a 1" graphite sur-platter, and an air bearing spindle to hold them. While each of them on its own rings when struck, the assembly is dead as a tomb. Just like the NA.

This assembly is mounted on a porous graphite air thrust bushing from New Way. The plinth is a complex of panzerholz and massive steel. Neither turntable is suspended. The NA plinth was replaced with an aluminum-baltic birch-aluminum sandwich.

Each turntable is fitted with a Trans-Fi Terminator air bearing tonearm. It is easy to exchange wands between them. Cartridge is a Koetsu Rosewood Signature Platinum with diamond cantilever. Phono stage is DIY full complementary push-pull with vacuum and air gap capacitors. Amps are DIY class A. Speakers are Quad ESL’s.

Now the experiment. The motors are disconnected, so that the essential difference between the TT’s is the friction in the bearing. Neither TT has an audible noise component when spinning - that is, audible at a few inches. The only indication of mechanical work being done in the NA is that the platter slows down.

The music produced by the DIY air bearing TT is notably more refined than the NA. Think of the difference between an electrolytic cap in the signal path compared to a film and foil cap. In the first few seconds, it seems like the air bearing is missing high frequency information, and in some sense it is - no high frequency distortion caused by bearing noise. But after listening for a minute or less, the difference (and preference) is clear: music from the air bearing is more natural and more musical.

After extended listening, it also turns out that the air bearing TT is less fatiguing (actually, not at all fatiguing). Furthermore, singers with unfamiliar accents or poor diction are more understandable. I conclude that bearing noise is a problem - and since I could hear bearing noise in the big new Technics DD, making it much inferior to the NA, it was easy to pass.

Mijostyn, you say, "... since when are air bearings not mechanical? There is a shaft in bushings just like any table except this one. "

Not so. Not at all. In my first post I specifically mentioned an air cushion in three dimensions. That is achieved by the New Way air bushings. Look it up.

Although the thrust bearing accounts for most of the friction, hence the noise, the shaft bearing generates enough noise to be easily noticeable. Please re-read my post regarding conclusions - noise is not in the 20Hz region, it's in the 5KHz region.

Further, @ct0517 notes how those attuned to such things can hear the difference between different engine oils. I expect that you can too - just before and after an oil change. It's not some deep psychological thing with your pride of ownership - the sound changes.

Last, I suggest that you conduct your own experiment. Get your platter up to speed by hand, and listen to the purity. Get that sound firmly in mind. Then disconnect the belt and do it again. It will sound different - and better - at least, it does with all 3 motors I have tried. What has changed is noise from the sleeve bearing on the motor - it's gone.

Quite so, lewm. Stability first.

Mijostyn, thanks for the nod, but beg to differ, although I daresay the big SME is a very fine turntable indeed.

@sedond   Thank you!