Upcoming Nagra turntable

[TLi]

Are there any other high end turntables with more than one motor?
Seems like multiple motors are a great way to increase torque without the drawbacks of a larger motor. And this is something you can’t do with direct drive.

Air Force One and One Premium use a fairly simple and small industrial motor. I have disassembled a AF1 motor housing and looked at the motor itself. Small motor has less vibration than a large one.

The problem with multiple motors is to get them to rotate in a synchronised way. The torque of most motors is not delivered in a continuous and steady way. It is like a gas engine in cars, the torque is provided by each stroke of cylinder, so it wobbles. More motors means more wobbles, it will just make things complicated.

Air Force Zero uses Papst motor which has a 3 phase 12 poles spindle. Each phase is driven by a separate amplifier circuit. It is like having three independent motors packed into one chassis. That's equivalent to 4 cylinder engine vs 12 cylinder one. The torque is larger and more steady. Together with air bearing and a large flywheel, the motor in AF0 is certainly one of the best, if not the best in a turntable system.

 

[Gregadd]

The problem is that a non direct drive tt is that it is always hunting for the correct speed. It constantly coasts below and above the exact speed.

 

[Zeotrope]

Air Force One and One Premium use a fairly simple and small industrial motor. I have disassembled a AF1 motor housing and looked at the motor itself. Small motor has less vibration than a large one.

The problem with multiple motors is to get them to rotate in a synchronised way. The torque of most motors is not delivered in a continuous and steady way. It is like a gas engine in cars, the torque is provided by each stroke of cylinder, so it wobbles. More motors means more wobbles, it will just make things complicated.

Air Force Zero uses Papst motor which has a 3 phase 12 poles spindle. Each phase is driven by a separate amplifier circuit. It is like having three independent motors packed into one chassis. That's equivalent to 4 cylinder engine vs 12 cylinder one. The torque is larger and more steady. Together with air bearing and a large flywheel, the motor in AF0 is certainly one of the best, if not the best in a turntable system.

It’s interesting that the Air Force Zero uses Pabst reel to reel motors. And we know which company has more experience than any with reel to reel machines…Nagra.
It will therefore be interesting to see the stats on the Nagra TT. I have a feeling it will have world-class speed control. When done right, two smaller motors spinning in opposing directions should have lower noise and better speed stability.

 

[Zeotrope]

The problem is that a non direct drive tt is that it is always hunting for the correct speed. It constantly coasts below and above the exact speed.

Not so. Certainly not in all cases. Direct drive are more prone to this if anything.

Remember it’s still a motor turning, regardless of whether there’s a belt between it and the plater or not. Without the gearing effect of the belt, the DD motor will need to be larger and more powerful. Larger motor = more torque = harder to finely control speed.

Looking forward to the first test of the new Nagra TT - I think a lot of people will be surprised.

 

[TLi]

The problem is that a non direct drive tt is that it is always hunting for the correct speed. It constantly coasts below and above the exact speed.

All turntables is constantly hunting for correct speed regardless of drive mechanism. The drag of stylus while playing is not constant. Drag is higher with more bass notes and lighter in quiet low volume passage.

The advantage of direct drive is the ability to quickly react to changes of drag and correct the speed accordingly. The response time is longer with bent drive because of the indirect drive from the bent. That is why direct drive TT often has better bass while bent drive has better treble.

The main problem with direct drive is motor noise. Any motor has noise (vibration), however small. This noise is transmitted to the platter via the spindle. Bent drive is often quieter than direct drive.

 

[PeterA]

Air Force One and One Premium use a fairly simple and small industrial motor. I have disassembled a AF1 motor housing and looked at the motor itself. Small motor has less vibration than a large one.

The problem with multiple motors is to get them to rotate in a synchronised way. The torque of most motors is not delivered in a continuous and steady way. It is like a gas engine in cars, the torque is provided by each stroke of cylinder, so it wobbles. More motors means more wobbles, it will just make things complicated.

Air Force Zero uses Papst motor which has a 3 phase 12 poles spindle. Each phase is driven by a separate amplifier circuit. It is like having three independent motors packed into one chassis. That's equivalent to 4 cylinder engine vs 12 cylinder one. The torque is larger and more steady. Together with air bearing and a large flywheel, the motor in AF0 is certainly one of the best, if not the best in a turntable system.

it’s a similar approach for motor design with fly wheel and bearing to the American sound turntables. I think in fact it’s the same motor.

things are improved further with a higher mass platter for inertia and non-stretch belt or thread drive with looser tension. This approach reduces further the influence of the motor pulley on the platter.

The less friction of the bearing the less the platter needs to be connected to the motor. The greater the inertia and the lower the friction, the more stable the speed.

 

[mtemur]

All turntables is constantly hunting for correct speed regardless of drive mechanism. The drag of stylus while playing is not constant. Drag is higher with more bass notes and lighter in quiet low volume passage.

The advantage of direct drive is the ability to quickly react to changes of drag and correct the speed accordingly. The response time is longer with bent drive because of the indirect drive from the bent. That is why direct drive TT often has better bass while bent drive has better treble.

The main problem with direct drive is motor noise. Any motor has noise (vibration), however small. This noise is transmitted to the platter via the spindle. Bent drive is often quieter than direct drive.

It’s not about the drive system it’s about platter mass. High mass platter can absorb slowing down caused by highly modulated grooves due to high stored energy but a low mass can not. Most direct drives have low mass platters and relatively high torque motors which cause high corrective force after a highly modulated groove and results increased flutter. Belt drives don’t do that even after a high corrective force is applied because belt smooths it out.

A direct drives applies corrective force excessively due to high torque and low mass. No matter what the manufacturers say this excessive force is inherit to direct drives and after slowing down by a high modulation of groove it causes spikes in speed til stabilization. Same thing happens on idler wheels too and these spikes on speed can easily be perceived as liveliness.

The slowing down happens afterwards the high modulation and no drive system can correct it while happening (if it’s not too long). Minimizing it by high mass platter and smooth reaction is more important than keeping exact 33.333 speed.

 

[Zeotrope]

What do you guys think of Nagra’s approach to speed regulation and the dual motor setup?

 

[andromedaaudio]

I think its a nice looking TT .
The whole set up in munich looked nice but sound wise it couldnt impress me .
But its not fair to blame it on the TT .
I would have liked to have heard it with different amps / speakers

 

[christensenleif@msn.com]

the Airtangent tt had 3 motors

 

[Gregadd]

You dance with the one who brought you. I am sorry but for that price Iwas expecting some audiophile jujewelry. At least adjustable speed with may a strobe. I am just saying.

 

[Zeotrope]

So the speed is adjusted during playback? I always thought that speed adjustment was done to ensure the platter is spinning at 33-1/3 as accurately as possible.

Nagra says no active speed control is employed during listening. @TLi this appears to be markedly different than TechDas' approach, for example. Curious what your impression is of the Nagra TT, @TLi !

In addition to the innovative two motor system, the turntable features a well thought out technology for absolute speed calibration. An accelerometer monitors the floating chassis to ensure that it is absolutely stable otherwise calibration does not take place. Calibration is done over a 20 second window during which time the platter’s speed is precisely calibrated during actual playback (stylus in groove). During this 20 second cycle the platter’s speed is compared with a high precision quartz reference. Any deviation from this absolute speed reference is corrected accordingly. An easy to read, distinctly Nagra Modulometer on the turntable’s front control panel makes calibration (and pitch control) simple. During listening no active speed control is employed. While listening, the motors are only running in a closed loop mode. By eliminating active speed control the “cogging” and associated ill effects on image stability generated by such active systems is avoided.

Nagra REFERENCE ANNIVERSARY TURNTABLE - Nagra

After 70 years in the analog, Nagra is proud to release the Reference Anniversary Turntable, the ultimate dream for analog passionates

www.nagraaudio.com

 

[Holmz]

All turntables is constantly hunting for correct speed regardless of drive mechanism. The drag of stylus while playing is not constant. Drag is higher with more bass notes and lighter in quiet low volume passage.

…

Is it?
I would think that it would be more constant or that the high freq would either contribute as much, or that HF would be less drag…?

 

[TLi]

Is it?
I would think that it would be more constant or that the high freq would either contribute as much, or that HF would be less drag…?

If you look at this video from 23:00 minute onwards Jonathon Weiss explains clearly the drag of stylus during playback.

 

[Zeotrope]

If you look at this video from 23:00 minute onwards Jonathon Weiss explains clearly the drag of stylus during playback.

View attachment 103608

No offence to you, but Jonathan Weiss doesn’t know very much about the science behind audio! Much of what he says is wrong - not all, but a lot
So quote anyone else, just not him.
There are videos where he says “all belt drive turntables are garbage”. And in others he calls audiophiles fools…
I would never have any of his products in my home, even if they were free.

 

[TLi]

No offence to you, but Jonathan Weiss doesn’t know very much about the science behind audio! Much of what he says is wrong - not all, but a lot
So quote anyone else, just not him.
There are videos where he says “all belt drive turntables are garbage”. And in others he calls audiophiles fools…
I would never have any of his products in my home, even if they were free.

I agree with you that his video and reasoning is full of biase. His comment on bent drive is certainly wrong. I only coded his part on changes on stylus drag during play. That part I agree with him.

 

[BillK]

Are there any other high end turntables with more than one motor?
Seems like multiple motors are a great way to increase torque without the drawbacks of a larger motor. And this is something you can’t do with direct drive.

Acoustic Signature’s higher-end tables have multiple motors, from two on the Hurricane NEO to six on the Invictus NEO.

 

[Zeotrope]

I

I agree with you that his video and reasoning is full of biase. His comment on bent drive is certainly wrong. I only coded his part on changes on stylus drag during play. That part I agree with him.

I see, got it, thanks.
But what do you think of Nagra’s approach to speed control? It seems like they do not adjust speed during playback?

 

[TLi]

I

I see, got it, thanks.
But what do you think of Nagra’s approach to speed control? It seems like they do not adjust speed during playback?

Neither do Air Force Zero, it is claimed constantly adjusting the speed will create more wobbles.
So there are more than one way to kill a cow. In the end, theory is theory. Listening is believing. I based most of my comments on actual listening experience.

 

[Zeotrope]

Neither do Air Force Zero, it is claimed constantly adjusting the speed will create more wobbles.
So there are more than one way to kill a cow. In the end, theory is theory. Listening is believing. I based most of my comments on actual listening experience.

I see, thanks. I would be very interested to hear what you think of the Nagra TT when you hear it.