Comparison of sonic qualities of some tonearms

@lewm The problem with the weight on a string AS mechanisms is that records are hardly ever perfectly concentric. Now the cantilever has to over come the stiction. I recall the old days with a V15 in an SME 3009. I use to watch the cantilever wag back and forth on eccentric records. If I defeated the AS the wagging stopped and the cantilever deflected towards the right channel. You can't win. You envision magnetic AS correctly. In the case of the Schroder CB one magnet is fixed to the horizontal bearing and the other on an adjusting screw. The neodymium magnets have opposite poles facing each other so they attract. When you study the geometry of the situation, the distance at the pivot really does not change that much as the tonearm travels over the record's playing surface.  If the AS is set at the center of the playing surface, so the variation to either side is only a few mm at the magnets, well within neodymium range. Yes, there is a slight variation across the record, the AS force dropping as the arm travels across the record. AS is a ball park situation and the CB's AS stays well within the ball park and I have measured this with the Wallyskater which can be adjusted to measure the AS anywhere on the record. It changes less than 1%, probably less than the pivoted style AS mechanisms like the Kuzma. 

@tomic601 my wife tells me I'm 1000% dog. I started painting my nose black back in 95 to get more attention. Growing a tail helped.

@asvjerry See, that tonearm has warped your brain. I had that H-K turntable and it warped mine. Tail wagging the dog. There you go, best use of a Rabco, as a car bomb. 

@billstevenson I can't imagine rewiring an arm would bother you that much.

@whart The Koetsu works reasonably well in the Airline because of it's very low compliance. The air bearing does absolutely nothing to alleviate the high horizontal mass, that would be magic. 

Frank Kuzma does one of everything to suite all comers or just to say he can. His unipivots are just as bad or as good as anyone's and the same holds true of the Airline. He can not even make his mind up on what kind of turntable to build, so he builds one of everything.

@pindac Removable head shells are for lazy people. It adds another set of contacts which is never a good idea. I like the Kuzma/Schroder solution which is a removable cartridge carrier without another set of contacts. 

I love how your physics is understood so as to justify your choices of components. But we all do that to some extent. There is a valid rationale for high horizontal effective mass which I’ve mentioned elsewhere and which I don’t feel like typing out yet again. If you have an LP that is so off center that it sets the AS weight into pendulum motion, then that LP needs to be re-centered with a reamer or trashed. IIRC, skating is worst at the outer and inner grooves, just  bc where the magnetic mechanism would be least consistent.

@mijostyn *L*  Y'all can blame a tonearm, but The Truth?

Lemme' show you the list I've compiled....

*Produces a roll, grabs loose end....roll hits floor and begins to uncoil,,,,*

Wanna start at birth or just cut to the grisly bits? ;)

Likely Rabco disappeared 'cuz of all the warped legal cases.....😏

@mijostyn said "The air bearing does absolutely nothing to alleviate the high horizontal mass, that would be magic. "

I understand- I guess, from my crude understanding of mechanics/physics, this is the difference between "weight" and "mass,"- that is, while the air bearing, properly designed to account for the load (of the entire arm "carriage") will relieve the weight or friction between the arm tube and the travel rail, the mass of the carriage remains the same.