American Sound, "The Absolute Nothing"

[bonzo75]

just for curiosity:
is "max free spin time" a goal in itself?
don´t get it

The longer that a platter can freely rotate the better quality the bearing as less drag. How much longer makes a difference is not clear. Is it that 5 mins is sufficient or 30 is required.

 

[Lagonda]

The longer that a platter can freely rotate the better quality the bearing as less drag. How much longer makes a difference is not clear. Is it that 5 mins is sufficient or 30 is required.

And some turntables add friction as part of the design, either by adding heavy oils in the bearing or some kind of friction clutch in old idlers.

 

[christensenleif@msn.com]

just know from changing bearings in the studer A80s, that the bearings with the least friction aren´t necessarily the quietest ones.....

 

[PeterA]

The longer that a platter can freely rotate the better quality the bearing as less drag. How much longer makes a difference is not clear. Is it that 5 mins is sufficient or 30 is required.

Nothing is required. Design choices and targets.

 

[Lagonda]

just know from changing bearings in the studer A80s, that the bearings with the least friction aren´t necessarily the quietest ones.....

Yes most of the Studer A 80 motors are somewhat noisy in the bearings, even when all friction parts are new. I own 3 of them. I will modify one with a air bearing at some point.

 

[Argonaut]

So … this turntable sports a bearing and a spindle , yet nothing is in direct contact with the platter other than a string drive chain whilst in operation ? What prevents horizontal drift ? And No I have zero desire to “Ask David”

 

[Mike Lavigne]

So … this turntable sports a bearing and a spindle , yet nothing is in direct contact with the platter other than a string drive chain whilst in operation ? What prevents horizontal drift ? And No I have zero desire to “Ask David”

that's secret stuff.

the CS Port 'air float' approach is a version of the same approach as the American Sound, and has a guide sleave the platter fits (is gently set down) into when it's installed. then when the air pressure is engaged the platter lifts with a film of air and is lifted off the base of the sleave too. not sure the details of the American Sound approach but 'guess' it's something similar.

it's not logical that there would not be a locating sleave of some sort for the American Sound. is this technically a bearing? don't know. on the CS Port, the 'air float' floats the whole bottom platter surface and the air escapes around the edges. but the platter does not touch the outside of the plinth, so it's the inner sleave where it is guided. does the air film also provide that air film around the sleave? so 'no touch'. probably.

CS Port is 'air float', not 'air bearing'.