Linear tracking turntables, whatever happened?

Uberwaltz - I agree with you
take for example another timing example.  
 
The original ET2 Air Bearing Linear tracker was introduced in 1980. The same year that CD was introduced. Bad timing ? yes, but thousands were still sold. Today they cost $5000 in US dollars new and without the pump system, but can be had for under $1000 used in good shape for an original version from the 80's.

Now unless someone has driven over one with their car ,there is nothing but a good isopropyl cleaning of the manifold's capillaries,  to bring it to factory specs. No mechanical bearing to deal with, no oil or lubricant to get hard over time. Unlike the Transfi with its multi bearing (air and mechanical), the ET2 is a full 360 enclosed air bearing. But it needs a pump with air line.  

My reference tonearm is a custom build ET 2.5. Once set up properly, it outperformed all previous tonearms including VPI 12, FR64s, and a Dynavector the last of which came to me on a Jean Nantais (his preferred arm) 100 lb Lenco. This TT had the same gear on it that Salvatore called the best he has heard with the first Ref 1.

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But it takes a Type A personality to own an ET2, not a Type B.
What is an Type A you ask ?

Well, think back to before GPS in cars. If you were out in the middle of nowhere and lost, would you

Type A) pull out the map and/or ask for directions. (or)

Type B) keep prodding on hoping to find your destination.

(Type B's should not own ET2's)

Anyway there is a whole thread dedicated to this unique tonearm if anyone is interested.  

Agreed about the Trans-Fi. Not only is it a good air bearing design, so the lateral forces acting on the stylus are negligible (think about the mechanical advantage of a spiral a meter long, acting over the width of a groove - a distance measured in micrometers), but it’s adjustable. As adjustable as any arm made, and that alone makes it a contender.

Let’s talk about adjustability. Tangentiality - fiddly, but perfectible. An old record, a good micrometer, a bright light, and half an hour. Mass - just add brass weights to the conveniently space holes. Resonance - lay Moongel or Sorbothane on the flat surfaces, as much or as little as required - as required for your cartridge and your taste.

VTA adjustment on the fly - and so easy it’s trivial. VTF a bit crude and fiddly, not on the fly, but intuitively obvious. Azimuth is the toughie - fiddly, but intuitive and very stable. Thing is, you start where most others end - and you end with 1 or 2 minute of arc precision (with a mod - see below).

Forget about overhang and choose-your-poison protractors which pretty much get it right - for parts of the record. And forget about almost-right-I-hope anti-skating. Instead, rejoice in Vic’s measurement about forces acting on the stylus - tonearm wire dominates.

Add the clever engineering which makes use of standard parts instead of precision machining, and you have a low-cost ultra high end device.

Is it perfect? No. The beam is cantilevered out, and so it’s just as unstable as other air bearing arms (that is, not very, but a little). The beam should hold adjustment to a few minutes of arc for perfect horizontal orientation. It doesn’t - it’s only stable to about 10 minutes of arc, but on the other hand, it’s a predictable amount in a predictable direction. I’ve built a support for the other end of the cantilever, and it solves both issues.

The vertical pivot is higher than the stylus by a centimetre or more. That means slightly compromised performance for warped records. The wand is only 70mm long, which accentuates the problem. On the other hand, the wand is only 70mm long. So that’s a tradeoff. In practical terms, it affects about 3% of my records negatively and 97% positively.

Last, there is a very minor aberration in air pressure on the saddle, for a few seconds, three or four times per side. The only cure is going to be an amorphous carbon bearing - costly, clunky, high pressure, and probably custom. But if I do that, I suspect I’ll have the best, most versatile cost-no-object tonearm in the world.

Or, you could settle for $15,000 performance for $1,000.

System - DIY air bearing TT, Koetsu, DIY electronics, ESL’s.

ok - I will rephrase.
The best linear tracker tonearms use the same force for movement across the record as a pivot arm - the groove.

@ct0517
That suggests the possibility of an air bearing.


I don't have a business relationship with Triplanar, just for the record. I do own two of his arms.


I saw a linear tracker eventually fatigue a Sumiko Boron to the point that the cantilever just fell off the cartridge. No particularly bad-ass records used. Prior to that happening, you could see the cantilever move from left to right. Clearly too much compliance.


I owned a Rabco for many years. I built a servo for it so that would be reliable. The servo also took some time to spin the motor up or down; in this way it would establish a speed depending on the cut of the record and didn't make a lot of motor noise. I also replaced the arm 'wand' with a carbon fiber setup that was lower mass. But the track that the arm ran on was its downfall- the track had resonance issues and used poor bearings to support the arm.

When the air bearing arms came out I took a good look at them, as I spent a lot of time at our first dealership, who also carried the arm. It gained a reputation for eating cantilevers. Clearly whatever cartridge you are using is more durable- what are you using?

Bergman is one manufacture that makes high quality tables another is Pre Audio http://www.charismaaudio.com/?page_id=3783

Terry, maybe you should have taken over for new production ; )

Interesting tweaks you have made there. You mean beam is manifold ? Then, may I ask how you have managed install the support for the other end ? To back of the plinth ? Maybe you could send me pics of it.
I have covered the saddle with damping sheet. I can cover the wand too if necessary (one cartridge benefits from damped wand). Do you think it´s an upgrade to cover the base as well although it´s quite sturdy ? The arm sits on a sturdy brass column on soapstone plinth.

Regards,