Ketchup, I have heard that before. And you are right, that's a helpful feature and not found in the majority of air bearing arms.
What it does is react to minor perturbations (and is thus an acknowledgment of the issue), but if you think about it, for best results it would have to be tuned to anticipate the compliance of the cartridge (I suspect it introduces LF noise too, translating the subsonic noise generated by the bending of the stylus that otherwise happens to a higher frequency). All that mass is still moving across the LP though, and its all being moved by that stylus. IOW, its a compromise but better than nothing!
There is a different issue that all air bearing arms have. Ever notice that if you have higher pressure pumps, reservoirs and regulators that the arm sounds better? There is a basic engineering problem at play. In LP playback, there can be no play between the platter surface and the mounting of the cartridge. This issue is very much akin to the steering in an automobile. If there is play between the steering wheel and the wheels of the car moving on the road, the result will be uncertain handling and could be dangerous!
In a turntable this sort of play is translated as a coloration in the sound. Anyone with an air bearing arm knows what I am talking about- the pumps and stuff I mentioned earlier. IOW, there is play that is inherent in the arm and there is nothing that can be done about it if the arm is to work.
This is why I favor the servo-controlled approach. Its a pity that there are no arms that have been developed to take advantage of recent materials advances in this area.
What it does is react to minor perturbations (and is thus an acknowledgment of the issue), but if you think about it, for best results it would have to be tuned to anticipate the compliance of the cartridge (I suspect it introduces LF noise too, translating the subsonic noise generated by the bending of the stylus that otherwise happens to a higher frequency). All that mass is still moving across the LP though, and its all being moved by that stylus. IOW, its a compromise but better than nothing!
There is a different issue that all air bearing arms have. Ever notice that if you have higher pressure pumps, reservoirs and regulators that the arm sounds better? There is a basic engineering problem at play. In LP playback, there can be no play between the platter surface and the mounting of the cartridge. This issue is very much akin to the steering in an automobile. If there is play between the steering wheel and the wheels of the car moving on the road, the result will be uncertain handling and could be dangerous!
In a turntable this sort of play is translated as a coloration in the sound. Anyone with an air bearing arm knows what I am talking about- the pumps and stuff I mentioned earlier. IOW, there is play that is inherent in the arm and there is nothing that can be done about it if the arm is to work.
This is why I favor the servo-controlled approach. Its a pity that there are no arms that have been developed to take advantage of recent materials advances in this area.