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Lewm
Interesting you mention the Kodo Beat. I have been following the evolution of this TT with interest, given it uses similar principles to the Final Audio.

01-04-14: Richardkrebs
The Beat appears to uses electromagnetic drag to "pre load" the motor. Moving the rotor back in phase relative to the rotating field.

Richardkrebs statement is wrong. It is the bearing that is preloaded in the Kodo. For those that have a grasp of basic engineering principles this is a common technique to assist with speed stability. Garrard used it with their eddy brakes. By including a drag component in a moving bearing the motor is always loaded to a minimum level. Preloading the motor so that it is working at a minimum level can help with speed stability.
I quote from the designer of the Kodo Beat review in Stereomojo :

The Beat has only one moving part: the bearing. Since this is the only internal source that can impart noise to the record, much care was taken to develop the bearing. Over engineering describes it nicely. It has a 25mm diameter spindle that is capable of handling a 100 pound plus platter (and yes, I did try one). There is a degree of resistance built in to the bearing and it too can be adjusted.

Now in terms of the AC motor itself, I quote from the manufacturers website:

The issue with DC motors is that their speed is affected by the load. That means they need a control circuit. The control circuit can make the average speed near perfect but this is achieved by constant speed adjustments so there will be constant small speed variations. Many high end tables have used extra mass in the driven rotational mass (platter) to help hide the speed corrections.

The answer came in the form of a huge 3 phase AC true synchronous motor. What makes this motor the best choice for a turntable is that its speed is not affected by load changes such as stylus drag and bearing oil temperature. When the load changes, such as stylus drag (yes, it is real) in complex music passages and heavy bass lines, a synchronous motor instantly draws more current and supplies more torque to the platter. This makes the controversial matter of stylus drag a non-issue. Because of this behavior, this type of motor does not need any form of servo circuit to control the speed when fed the proper power.

So contrary to the statement by Richardkrebs above, AC synchronous motors lock in and do not “phase lag”. If an AC synchronous motor sees additional load, it automatically draws more current and supplies more torque to the platter.
From the manufacturers website

This power is supplied via a sophisticated and very accurate power supply designed to give The Beat clean and consistent power with correct frequency, no matter how dirty your mains supply. This power supply also gives the audiophile another feature, adjustable motor torque. Every listener seems to enjoy a slightly different take on his music so The Beat lets you adjust the torque of the drive system.

In summary, the Kodo Beat TT includes:
High torque AC motor with no servos
Carefully designed platter weight (11kg) to match the high torque AC motor
Accurate power supply that provides the correct frequency to lock the AC motor regardless of the mains power
Adjustable torque controller to optimize the drive
1” bearing designed for loads to 100lbs+.

In comparison the Final Audio Parthenon, built in 1971 uses :
High torque AC motor with no servos
Carefully designed platter weight (22kg) to match the high torque AC motor
Accurate power supply that provides the correct frequency to lock the AC motor regardless of the mains power ( Sine & cosine wave generators and power amplifiers are used in the Final power supply )
Adjustable torque controller to optimize the drive ( prior to the Beat, the Final is the only TT I have seen with adjustable torque ).
1” bearing designed for loads to 100lbs+.

The differences between the Beat and the Final Audio Parthenon are :
The Beat utilises Magdrive, the Final Audio is thread drive.
The Beat appears to use a conventional T bearing ( that’s T for Topple in engineering terms ), whereas the Final uses an inverted bearing placing the centre of gravity of the platter well below the bearing point.

The closest equivalent for the Final Audio TT is its granddaughter - the Kondo Ginga at quoted retail prices of approximately US$80k

In my view the Kodo Beat is a well conceived design and at US$24000 appears to be a bargain.

HF Dover

You appear to have invented a whole new type of motor. One where the rotor follows the rotating field with zero phase lag.
Please explain to us all how such a motor produces any torque.
Also one which "Instantly" draws more current and supplies more torque.
Please explain to us how it senses the need for more torque.

Caution needs to be exercised when quoting manufacturers advertisements.

Regarding the eddy current brake as used in the Beat TT
Go to teresaudio.com and follow the link...micro precise speed technology.
The Certus motor.
As I said earlier, this is an elegant design.

"The Beat [like every other direct-drive turntable] has only one moving part, the bearing." The ad copy is correct; however the inference that this quality is exclusive to the Beat is exaggerated, to say the least. But I really really like the Beat. I think it may be the best buy in high end turntables, if $24K is a "buy", but I can live without the hype.

I think I mentioned this above; the Denon DP80 and other models use a genuine 3-phase AC synch motor. But they also built in quartz-referenced servo control. The servo can be defeated on the front panel. It would be interesting to compare its performance with vs without the servo engaged, but you might fairly say that the platter is not massive enough to give the momentum needed for the a non-servo dd to perform really well, even with an AC synch motor.

But isn't the argument that a massive platter and no servo is superior to a lower inertia platter WITH servo just an analog of an old argument among belt-drive aficionados, where the two sides argue over massive platter/weak motor vs lighter platter/torque-y motor? The more things change, the more they stay the same. Massive platters tend to "spread out" any speed error over time. Those who like them say that this is good. Those who don't don't.

And now we have "Mag-drive", because the buying public have been taught for 30 years that direct-drive is a dirty word.

01-05-14: Richardkrebs
Regarding the eddy current brake as used in the Beat TT

Please quote the authority to substantiate your assertion that the Beat uses an eddy brake ?