American Sound, "The Absolute Nothing"

[djsina2]

Wasn’t it mentioned before that AS-2000 and AN uses a true air bearing, as in no platter contact with a bearing? I thought I read that from you in one of these threads.

 

[Ron Resnick]

The platters have less ability to stabilize platter speed when they are low mass and higher bearing friction. They move quicker because of less inertia, and they are more susceptible to influence from the drive. That is how I understand it. You asked how the AS 2000 maintains speed. The platter and bearing are a part of it. I would not say the same about my former SME turntables or my Denon DD, or the Garrard idlers I have seen. In those cases, the motor and controller have greater influence on final platter speed.

I am happy to be corrected and learn from someone who knows more than I do on this subject. I related to you my direct experience from living with two SMEs, a DD Denon, the Micro, the AS 1000 and the AS 2000 from setting them up, experimenting with thread/belt tension, and observing bearing friction all while measuring results with my Timeline strobe and some with the Roadrunner Tach. If the issue is maintaining smooth, constant speed, the American Sound tables were better than those others, in part because of the platter mass and low bearing friction. I suspect the platter mass and bearing type have other advantages in terms of noise also, but that is a different topic.

To improve on the AS2000 performance, David too his new design to extremes. The platter is wider and taller, for about twice the mass and greater interia. The bearing is similar. The motor is the same but the controller is improved as is the motor housing.

Other typologies also maintain accurate and consistent speed like my Denon and my friend's SP10 MKIII. There are lots of approaches. Good speed is but one of the elements for good sound.

You should interview some turntable designers. Ask them these questions. It would be fascinating and I am sure very educational.

Thank you.

 

[PeterA]

Wasn’t it mentioned before that AS-2000 and AN uses a true air bearing, as in no platter contact with a bearing? I thought I read that from you in one of these threads.

I have written that the three American Sound turntables have platters that are supported by a cushion of air. There is zero contact with the base. The only contact the platter sees is with the belt or thread and with the stylus. I have found that thread tension is important. The looser it is, the less influence from the motor on the platter, and sound improves. It can not be too loose because there must be some control from the motor. The speed consistency is remarkable considering there is no correction taking place. The motor spins at a given speed without adjusting once it is set to the frequency. At least this is how I understand it.

 

[tima]

In a direct drive with lightweight platter how are the motor and the platter not responsible for maintaining steady speed? Yes, it has an electronic controller using a servo, but the AS-2000 also has an electronic controller, so I don't see a conceptual difference there.

Too rudimentary.

- In the case of the DD platter, less dependancy on mass and inertia.
- In the case of the DD motor, it is not responsible for maintaing speed, it is responsible for following directives from the controller.

A lightweight platter whose speed is monitored multiple thousand times per revolution is capable of high stable speed accuracy.

 

[tima]

I believe Tang is still secretly listening to music. The broken system is a elaborate excuse concocted to gracefully get out of sending the 10 video recordings of classical music Ked requested every week. I have heard rumors of WBF members going into witness protection to avoid Ked's video requests !

For bonzo, maybe a handful of dimes and a jukebox ...

 

[andromedaaudio]

For bonzo, maybe a handful of dimes and a jukebox ...

May be you can start a crowdfunding

 

[howiebrou]

He has lost hifi enthusiasm, I can’t explain why.

So will I if I continue reading this thread...

 

[bonzo75]

So will I if I continue reading this thread...

We can start a food fight so you lose eating enthusiasm

 

[howiebrou]

We can start a food fight so you lose eating enthusiasm

If only it worked that way. May be hide some Ozempic needles in the Eton Mess?

 

[bonzo75]

Of only it worked that way. May be hide some Ozempic needles in the Eton Mess?

Lyle's, which is one of the best fine dining restaurants in London has Damson and Walnut mess this month - changes frequently though.

 

[andromedaaudio]

Dont worry guys .
The magazines in the US will direct you in what you need to buy next .
Monthly updates for gear replacements to keep you going
So you don t get bored

 

[spiritofmusic]

So will I if I continue reading this thread...

It's like anti-Viagra.

 

[Lagonda]

For bonzo, maybe a handful of dimes and a jukebox ...

He has his soundbar !

 

[Al M.]

It's like anti-Viagra.

Who needs Viagra?

 

[mtemur]

Wasn’t it mentioned before that AS-2000 and AN uses a true air bearing, as in no platter contact with a bearing? I thought I read that from you in one of these threads.

Good question! I’m curious about the implementation as well. Perhaps the bearing only makes contact with the platter horizontally?

 

[djsina2]

I have written that the three American Sound turntables have platters that are supported by a cushion of air. There is zero contact with the base. The only contact the platter sees is with the belt or thread and with the stylus. I have found that thread tension is important. The looser it is, the less influence from the motor on the platter, and sound improves. It can not be too loose because there must be some control from the motor. The speed consistency is remarkable considering there is no correction taking place. The motor spins at a given speed without adjusting once it is set to the frequency. At least this is how I understand it.

You mentioned bearing friction in your other post so I was confused.

 

[Mike Lavigne]

A lightweight platter whose speed is monitored multiple thousand times per revolution is capable of high stable speed accuracy.

but does it project the feeling of musical flow and liquidity? to what degree?

or is it a bit stark and bare sounding.....relatively? i had the first gen GPA Monaco turntable in my room for a year which most definitely was stark and bare sounding. digital sounding even.

the following is my own translation from Jinglish which had been posted on the CS Port website back a few years ago. not say it's like this, but to a degree it might be.

In order to pick up sound accurately from the analog disc, the rotation of the platter must be rotated at a constant speed without any “fluctuation”. In general, accurate rotation is obtained by servo control by negative feedback, but at the micro level, if it rotates or becomes faster, it detects it and slows it, and repeats the operation to make it faster if it gets slower. Although this level and cycle are determined by the gain of the control system and the loop speed, the period of the speed control of the platter which is the mechanical system surely comes into the audio band. In general, accurate rotation is obtained by servo control by negative feedback, but at the micro level, if it rotates or becomes faster, it detects it and slows it, and repeats the operation to make it faster if it gets slower. If you try to measure a period with a small level, you can not measure the instantaneous state, so you measure the average value. Therefore, fine vibration generated by servo control can not be measured by the measuring instrument, it depends on the human ear.

for whatever reason, my Esoteric T1 which is a magnetic drive/rim drive idler, with a servo, become more 'human' and had greater 'flow' when i added the clock. it was not lacking flow without the clock, but had more with it.

my newer Wave Kinetics NVS direct drive turntable with a newer motor drive algorithm had much better flow.

my Rockport Sirius III direct drive with servo had excellent flow, but the execution of the every aspect of the design was extreme.

servos, feedback loops, and all things related do matter for speed control. alot. probably platter mass too.

 

[PeterA]

You mentioned bearing friction in your other post so I was confused.

My understanding is that air causes friction between the surfaces, but it is minor as indicated by the free spin time to rest for the platter. Sorry, Ron.

 

[christensenleif@msn.com]

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

 

[PeterA]

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

That is a good question for the turntable designers. Free spin time is an indication of friction. Intuitively, it seems the longer a platter can spin on its own, the less influence it needs from the motor to maintain a constant speed. In some designs, this may be advantageous. Different approaches with different levels of implementation. We can see from all the different turntables out there that designers address speed differently.