Linear tracking turntables, whatever happened?

The best linear tracker tonearms use the same force for movement as a pivot arm - the groove.

This depends on what is meant by this statement.
A number of linear trackers employ an air bearing, and thus have lateral tracking mass that is several times that of the vertical tracking mass. Quite often with such arms the side to side forces on the cantilever become the tracking angle error! This can exceed a good radial tracking arm.


So I'm not sure that qualifies as 'The best'.


A servo to control the rear of the arm as the arm moves across the LP (such as the old Rabco SL8) is a better solution, although the Rabco itself had many other problems. But if a modern version of such an arm were built, it could easily solve most of the issues that were a plague to the Rabco.

Ct, In the absence of any friction at the pivot point, yes there is no need for any external force to move the arm wand/cartridge across the LP surface.  However, in the real world, there is never zero friction.  Thus we first had the Rabco SL8, referred to by Ralph, which used a servo motor to nudge the pivot each time the arm wand moved in tiny arcs at the stylus contact point; the Rabco makes a series of tiny arcs all across the LP surface, the servo motor makes noise, yadayada.  Arguably, it's not even a true SL tonearm.  The Goldmund TF tonearm is naught but a very expensive copy of the Rabco idea.  We also have the Souther tonearm which operates in concert with a "dished" platter (marketed in recent years by Clearaudio), so that the cartridge "falls" toward the spindle whilst riding on a rail.  The most pure form of the art is the air bearing type, which at least strives for zero friction.  But since that is impossible, side forces are created, as described by Ralph. In addition, one must fuss with air pumps, etc. But certain examples, like the Terminator, can be very good. I don't need to own an SL tonearm or turntable in order to know these things.  What about you?

The only full bore turntable/SL tonearm available now comes from Germany, I think, but I cannot recall its name.  Another German company, Brinkmann may also make one.

Atmasphere.

The best linear tracker tonearms use the same force for movement as a pivot arm - the groove.

This depends on what is meant by this statement.

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

Atmasphere
Quite often with such arms the side to side forces on the cantilever become the tracking angle error! This can exceed a good radial tracking arm.

Firstly - no one I know that owns an expensive tonearm any type - plays bad-ass records where side to side forces on the cantilever become any type of problem. A quick call to Peter at Soundsmith on what he sees when he fixes carts, will illuminate all on side forces with improper anti skating.  
I was talking about the best ones only Atmasphere. Don't be general in your statement Give examples please; maybe in a thread on this topic, and when posting about tonearms in general;  I personally feel you should be using your business partnership with Tri-planar disclaimer on each post.   

Cheers

Lewm - so I take it then that your answer is NO  - you have never owned a Linear tracker in your room ?

I've been running a Kuzma Airline for more than 12 years. I like it, it is made well, no issues other than dealing with air compressor, which adds an additional layer of complication to what is otherwise a pretty straightforward design and execution. Otherwise, pretty easy to set up and dial in, minimal maintenance.
I gather the Trans-Fi is the cat's meow at an easily digestible price. 
I remember the Rabco. I think the arm on the Goldmund Reference (old) was similar, but there were/are tweaks to get it to play nicely. 

These are very good comments but I am still left wondering what was wrong with the general consumer models like the Revox, B&O, Technics etc that caused their lack of acceptance.
Surely it was not just all down to the fact that people treated them more like cd players as alluded to?