American Sound, "The Absolute Nothing"

[christensenleif@msn.com]

Some claim a mechanical anchoring of the spindle/platter is better than an air bearing
One of them I believe is Tommy Hørning

 

[PeterA]

That's why you need high air pressure on the axial bearing to absorb lateral forces, e.g. belt tension, so that the spindle doesn't lean against the bearing surface when the platter rotates. I wouldn't build anything with air bearings these days, there are bearings that don't need lubrication anymore, e.g. CMB (Clearaudio) or S Grün from TW Acustic. If a bearing doesn't need lubrication, you can be sure that the friction is very low.

You could get some indication of how low that bearing friction is by hand spinning the platter to 33 RPM and seeing how long it takes to stop.

 

[DasguteOhr]

The main advantage with a air bearing is the possibility to use a very heavy platter, without much friction. The disadvantages are need of air supply and the potential noise, with some industrial bearings you need very high pressure and very clean air.

Its ok when it works for you and you are happy with it.
there are other good solutions, tungsten carbide bearing max load 600lbs. with 40lbs flywhell 800rpm and 110lbs platter. the best sounding turntable i ever heard in my life. stability in tones is unsurpassed. e.g. piano.

Next year i get it i hope so.

 

[Lagonda]

Its ok when it works for you and you are happy with it.
there are other good solutions, tungsten carbide bearing max load 600lbs. with 40lbs flywhell 800rpm and 110lbs platter. the best sounding turntable i ever heard in my life. stability in tones is unsurpassed. e.g. piano.View attachment 136296

Next year i get it i hope so.

Are you waiting for someone to die and leave it to you in his testament ? Very interesting belt setup, what motor does it use ? Love the loose transformer on the floor, better lock up your kids, dogs and cats !

 

[Mike Lavigne]

Some claim a mechanical anchoring of the spindle/platter is better than an air bearing.

i enjoy having both in my system. visitors many times have a preference. both ways. of course, there are many variables besides the bearing type too, so it's not any truly scientific compare. but presentation can be right both ways.

one tt having both an air float for the platter and an air bearing for the arm i think makes the differences more pronounced and easier to grasp.

 

[DasguteOhr]

Are you waiting for someone to die and leave it to you in his testament ? Very interesting belt setup, what motor does it use ?

No, he gave up the hobby. Sold it to my cousin three years ago. I'm building him a nice tube amplifier in exchange. Revox A77 motor, belt rubberized Kevlar tape. With capstan shafts almost 100% wrap angle on the platter for perfect power transmission.

P.S
the upper part of the platter is noise protection glass no contact with the spindle of bearing

 

[Maril555]

Thanks for the explanation, but I highly doubt that any turntable uses a full air bearing where the platter is in contact with nothing but an air cushion. I’m almost certain of this because I haven’t seen any concrete proof, just vague explanations from manufacturers that seem evasive. Since full air bearings are industrially available, I don’t believe it’s a patent or company secret issue, but rather a challenge of implementation. I suspect there is a sleeve bearing or something similar to prevent lateral movement caused by the belt, motor, or occasional contact with the platter while changing records. Additionally, there must be some kind of thrust bearing to maintain the air gap between the platter and plinth when placing a record, using a heavy stabilizer, dealing with changes in air pressure, or when the platter is accidentally bumped.

I think after Peter A. emphasized multiple times that there is ZERO physical contact b/w the platter and the plinth that should be sufficient to stop the argument.
In discussing the issue with David himself, it is my impression of the design as well. Granted I’m not as familiar with the details of it as Peter is.
The explanations of the design are “vague and evasive” on purpose, since it’s proprietary and David doesn’t want to divulge it.
And I don’t think he is under any obligations to provide a proof of the concept.

 

[mtemur]

I think after Peter A. emphasized multiple times that there is ZERO physical contact b/w the platter and the plinth that should be sufficient to stop the argument.

He clearly said that he doesn't know exactly how it is.

The explanations of the design are “vague and evasive” on purpose, since it’s proprietary and David doesn’t want to divulge it.

Really?

 

[mtemur]

And I don’t think he is under any obligations to provide a proof of the concept.

This argument, especially my posts are not only about American Sound turntables. It is about the concept of air bearing.

 

[Argonaut]

I think after Peter A. emphasized multiple times that there is ZERO physical contact b/w the platter and the plinth that should be sufficient to stop the argument.
In discussing the issue with David himself, it is my impression of the design as well. Granted I’m not as familiar with the details of it as Peter is.
The explanations of the design are “vague and evasive” on purpose, since it’s proprietary and David doesn’t want to divulge it.
And I don’t think he is under any obligations to provide a proof of the concept.

Bollox !!!