Holbo mk2 Airbearing Turntable System

[hb22]

About the airbearing for the platter, may I ask whether it is airbearing for both the vertical and horizontal / radial planes, or only for the vertical plane like the Micro Seiki / TechDas ? Thanks

In the case of the Holbo mk2 turntable, the air bearing is only in the vertical plane. Even a 5 kg platter works and plays very well. The height of the air gap and the medium in the sliding bearing greatly affect the sound and the final result. You can choose from a huge number of materials for its manufacture, because there are no large loads in the radial direction. The medium in the sliding bearing of the Holbo mk2 tt is neither oil nor grease. It greatly affects the sound.

To make it clear what I'm talking about, below is a picture of a real air bearing, which I made more than 30 years ago. Of course, it has its advantages, but the cost of manufacturing and the weight of the platter it carries are enormous and I can't calculate it for a normal price of a turntable. A real air bearing requires a platter that weighs at least 50 kg for correct sound.

 

[DasguteOhr]

When you want build a air bearing system, the rolls royce under the air bearings.
Sorry, offtopic I couldn't hold back.

Air bearing - Aerolas Produkte

Air bearing Selection of products Selection guideConstruction guideManual Flat […]

produkte.aerolas.de

 

[hb22]

When you want build a air bearing system, the rolls royce under the air bearings.
Sorry, offtopic I couldn't hold back.

Air bearing - Aerolas Produkte

Air bearing Selection of products Selection guideConstruction guideManual Flat […]

produkte.aerolas.de

I know Unterhaching-Ottobrun very well and I also know the Areolas company. When I went to them with my sketch-plan of an air bearing, they told me that it couldn't be made. But my collaborators did. That was many years ago. Not every air bearing is ok for audio purposes.

 

[mtemur]

@hb22 I wish you the best of luck and success with your new turntable. I agree — heavy platters on air bearings can sound fantastic.

IMHO, offering the Holbo Mk2 without an arm would be a smarter move, giving customers more freedom to choose what best suits their liking.

 

[hb22]

@hb22 I wish you the best of luck and success with your new turntable. I agree — heavy platters on air bearings can sound fantastic.

IMHO, offering the Holbo Mk2 without an arm would be a smarter move, giving customers more freedom to choose what best suits their liking.

I actually have no intention of making another turntable. I really like the Holbo mk2 and I'm sure I'll sell a lot more of them. I did this test with a 40 kilo platter to test the tonearm. And it's true as I've always said: the Holbo tonearm has top-notch bass, it sounds really good now. The Holbo mk2 is a top-notch turntable + tonearm. The only problem is that it's cheap.

 

[mtemur]

About the airbearing for the platter, may I ask whether it is airbearing for both the vertical and horizontal / radial planes, or only for the vertical plane like the Micro Seiki / TechDas ? Thanks

How do you know Micro and TechDAS air bearings are only for the vertical plane? Do you have proof?

Don’t get me wrong — I agree that most air bearings on turntables act only in the vertical plane; there’s usually a sleeve or journal bearing to control the horizontal plane. Frankly, I’d be skeptical of using air for the horizontal plane myself.

That said, I haven’t seen any convincing evidence that a turntable uses air bearings for both axes. If someone claims otherwise, they should show facts: technical drawings, teardown photos, manufacturer specs, or lab measurements — not just assertions.

 

[spiritofmusic]

Doesn't DDKs uber UBER tt that PeterA owns run air bearings in both planes?

 

[mtemur]

Doesn't DDKs uber UBER tt that PeterA owns run air bearings in both planes?

I don’t know — does it? Is there any actual proof or clue beyond just words?

Besides, discussing someone’s DIY turntable doesn’t really make sense. In my opinion, we should focus on established, widely available commercial products instead.

 

[bonzo75]

Doesn't DDKs uber UBER tt that PeterA owns run air bearings in both planes?

Peter owns the entry level uber at 100k, not the uber UBER at 400k

 

[spiritofmusic]

uber or uber UBER...more confusing than looking for your Uber in a car park full of Ubers.

 

[DasguteOhr]

I know Unterhaching-Ottobrun very well and I also know the Areolas company. When I went to them with my sketch-plan of an air bearing, they told me that it couldn't be made. But my collaborators did. That was many years ago. Not every air bearing is ok for audio purposes.

Ok. I understand
Too complicated for me. I switched to tungsten carbide - Teflon S green bearings. Continued good sales figures with your turntables.

 

[djsina2]

I don’t know — does it? Is there any actual proof or clue beyond just words?

Besides, discussing someone’s DIY turntable doesn’t really make sense. In my opinion, we should focus on established, widely available commercial products instead.

My Audio Tekne is air in both planes.

The Holbo seems like an incredible value based off user feedback and what you get.

 

[thekong]

How do you know Micro and TechDAS air bearings are only for the vertical plane? Do you have proof?

Don’t get me wrong — I agree that most air bearings on turntables act only in the vertical plane; there’s usually a sleeve or journal bearing to control the horizontal plane. Frankly, I’d be skeptical of using air for the horizontal plane myself.

That said, I haven’t seen any convincing evidence that a turntable uses air bearings for both axes. If someone claims otherwise, they should show facts: technical drawings, teardown photos, manufacturer specs, or lab measurements — not just assertions.

In the attached technical drawing of the TechDas Airforce One Premier, they used two different terms to describe the bearing: “Air Bearing, floating height 0.05mm” and “Maintenance-free Radial Bearing Assembly . Heat-treatment SUS 4 20/2 Shaft and Self-lubricanting Bearing“ . So, I am pretty sure that airbearing is only for the vertical plane, much like the Micro Seikis .

Yes, as far as I understand, very few turntables use airbearing for both axis, the few I know of including a few of the Rockports, the Versa Dynamics , and the Kuzma XL Air.

Attached is a photo of the airbearing of my Rockport Sirius II. I think here is the current version (or maybe very similar) of that bearing : https://www.newwayairbearings.com/catalog/air-spindles/

 

[mtemur]

The Holbo mk2 is a top-notch turntable + tonearm

If that’s true why did you even bother testing with a 40 kg platter.

The only problem is that it's cheap.

I believe that holbo turntable is very good for its price.

 

[hb22]

If that’s true why did you even bother testing with a 40 kg platter.


I believe that holbo turntable is very good for its price.

Of course, the 40 kg plate has stronger and more realistic bass. It is also true that I changed the phono cable from VDH to Cardas, and this one actually has more pronounced bass. I am waiting for the VDH cable with the TAC connector to actually confirm the difference.

 

[mtemur]

In the attached technical drawing of the TechDas Airforce One Premier, they used two different terms to describe the bearing: “Air Bearing, floating height 0.05mm” and “Maintenance-free Radial Bearing Assembly . Heat-treatment SUS 4 20/2 Shaft and Self-lubricanting Bearing“ . So, I am pretty sure that airbearing is only for the vertical plane, much like the Micro Seikis .

Yes, as far as I understand, very few turntables use airbearing for both axis, the few I know of including a few of the Rockports, the Versa Dynamics , and the Kuzma XL Air.

Attached is a photo of the airbearing of my Rockport Sirius II. I think here is the current version (or maybe very similar) of that bearing : https://www.newwayairbearings.com/catalog/air-spindles/

Thanks for sharing the technical drawing. As I said before, I agree with you that the air bearing functions only on the vertical plane. In fact, TechDAS turntables float the platter at a height of about 30 microns, not 0.05 mm. Other air-bearing turntables also maintain a platter float of around 30 microns. Perhaps the design has changed since the drawing you shared, and the air bearing itself may have been revised as well.

Besides employing regular sleeve or journal bearings for the horizontal plane, I think ensuring a proper thrust bearing is more critical. If a thrust bearing is used, employing an air bearing for both the horizontal and vertical planes makes more sense, since a ball or spike-in-cup type thrust bearing can restrict movement in both directions.

 

[thekong]

Of course, the 40 kg plate has stronger and more realistic bass. It is also true that I changed the phono cable from VDH to Cardas, and this one actually has more pronounced bass. I am waiting for the VDH cable with the TAC connector to actually confirm the difference.

So, the current airbearing can support the 40kg platter without modificaton? If so, good for you!

 

[thekong]

Thanks for sharing the technical drawing. As I said before, I agree with you that the air bearing functions only on the vertical plane. In fact, TechDAS turntables float the platter at a height of about 30 microns, not 0.05 mm. Other air-bearing turntables also maintain a platter float of around 30 microns. Perhaps the design has changed since the drawing you shared, and the air bearing itself may have been revised as well.

Besides employing regular sleeve or journal bearings for the horizontal plane, I think ensuring a proper thrust bearing is more critical. If a thrust bearing is used, employing an air bearing for both the horizontal and vertical planes makes more sense, since a ball or spike-in-cup type thrust bearing can restrict movement in both directions.

I am not sure whether the drawing of the TechDas AF1P is current, but I have just copied it out from their website today!

Agreed, I also think having a thrust bearing would be beneficial for an airbearing of both axis, kind of like the one in the JC Verdier La Platine magnetic bearing! While I don’t think it can be implemented in the New Way style airbearing, it probably can be implemented in the Kuzma XL Air style bearing. You can take a look at the bearing in their manual here:

https://www.kuzma.si/media/uploads/files/IM%20XL%20AIR%20220627.pdf

 

[hb22]

So, the current airbearing can support the 40kg platter without modificaton? If so, good for you!

Yes, that's right. And the same motor and air pump from the Holbo mk2.

 

[DasguteOhr]

The bearing had no axle ,below 17 degrees Celsius room temperature, the air bearing jammed, and above that a 50 kg plate came to life and rotated. The manufacturing precision of these bearings is impressive 30 years ago( Vertical air gap 5/1000 millimeters, horizontal air gap 1/10000 millimeters). A bearing like this makes a DIY solution unaffordable.
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