Dover, to suggest that the Trans-Fi arm "is not a very good design at all" due to possible bearing wobble ignores a complex of variables.
Unlike any captured air bearing design, this is a mechanical pivot arm in the vertical plane and an air bearing in the horizontal plane. As all air bearings move freely in the horizontal, the possibility of wobble is relevant only in the vertical plane. The vertical needle pivot points hang in a cradle well below the air bearing. (The two needle pivots are also spaced apart by a generous 2.5" for stability.) It would be complex math to model this system precisely, however it is easy to see that the system is relatively stable, as by definition the mechanical pivot is absorbing most of the vertical dynamics of the arm. (Picture a see-saw that pivots on the seat of a swing. Will the action of the see saw move the swing?)
The stability of the air bearing itself is a function of a several factors: the surface area of the bearing(a generous 14 sq. in.), the length of the sled(a generous 7"x 2" "air foil" that rides like an airplane wing (an airplane wing of sufficient size for its fusilage and cargo becomes stable, No?)
There are also other variables operating on the comparison bewteen these arms: short arm vs. long arm resonance characteristics, lighter vs. heavier vertical inertial mass characteristics, low vs. high air pressure turbulence/pulsing characteristics transmitted to the stylus.
The complex of variables in each these arm should be considered in totality. As in all things audio, it's disingenuous to generalize.
Lewn, BTW there is not moisture issue with this arm since there is no compressor tank. The bearing operates at the same 1 psi output as produced by the aquarium pump.
Unlike any captured air bearing design, this is a mechanical pivot arm in the vertical plane and an air bearing in the horizontal plane. As all air bearings move freely in the horizontal, the possibility of wobble is relevant only in the vertical plane. The vertical needle pivot points hang in a cradle well below the air bearing. (The two needle pivots are also spaced apart by a generous 2.5" for stability.) It would be complex math to model this system precisely, however it is easy to see that the system is relatively stable, as by definition the mechanical pivot is absorbing most of the vertical dynamics of the arm. (Picture a see-saw that pivots on the seat of a swing. Will the action of the see saw move the swing?)
The stability of the air bearing itself is a function of a several factors: the surface area of the bearing(a generous 14 sq. in.), the length of the sled(a generous 7"x 2" "air foil" that rides like an airplane wing (an airplane wing of sufficient size for its fusilage and cargo becomes stable, No?)
There are also other variables operating on the comparison bewteen these arms: short arm vs. long arm resonance characteristics, lighter vs. heavier vertical inertial mass characteristics, low vs. high air pressure turbulence/pulsing characteristics transmitted to the stylus.
The complex of variables in each these arm should be considered in totality. As in all things audio, it's disingenuous to generalize.
Lewn, BTW there is not moisture issue with this arm since there is no compressor tank. The bearing operates at the same 1 psi output as produced by the aquarium pump.

