Is tonearm bias a compromise, maybe a myth?

"Pre-loaded" implies to me that there is a load on the cantilever independent of the stylus being played in the groove.

Sorry. By "pre-loaded" I mean that A/S devices pressure the cantilever against the suspension as soon as the stylus locks into a groove. I could have called this "loading" rather than "pre-loading"

It seems to me that there is no load on the cantilever until it hits the groove.

Agreed.

If the record is not spinning, with no anti skating force, the load is only vertical if the stylus is in
the groove.

Correct.

You write: The pre-loaded force is "pressuring it (the cantilever) against the elastic suspension reducing its freedom to respond to groove transients." My question is: Isn't this exactly what skating force does if you don't apply anti-skating force? It seems to me that skating force is also "pressuring it against the elastic suspension reducing its freedom to respond to groove transients."

Skating forces do load the cantilever against the suspension but anti-skating devices do not counteract that loading, they actually increase it.

Imagine that your hands are very small. Grab the STYLUS with your L hand and pull it toward the record center. That's skating and yes, you can feel the squidginess of the suspension being compressed by the far end of the cantilever as you tug.

Now grab the TONEARM with your R hand and pull it away from the record center. That's anti-skating. If the stylus is locked into a groove you'll feel a similar squidginess as the cantilever compresses the suspension.

Now pull simultaneously with both hands (which represents playing a record with A/S engaged). If you pull equally hard with each hand the pressure you apply to the suspension is doubled. It's that much closer to "bottoming out".

While you have these tiny hands, try shifting your R hand to the stylus and pulling it outward just as your L hand is pulling it inward. What happens to the cantilever/suspension interface ? Nothing! No squidginess. The two forces are now aligned and precisely oppose each other. That's how a perfect anti-skating device would work. It would negate skating forces without effecting cantilever freedom.

Of course nobody has built such a device and it's unlikely anyone ever will. The compromises necessitated by real-world design considerations mean that A/S devices pull on the tonearm while skating forces pull on the stylus. Result: increased dampening of the cantilever (squidginess).

***

As to what you hear in your system vs. what we hear in ours, every system differs and the listener's ears must be the judge, as we both keep saying. Your cartridge, tonearm and electronics are quite different to ours. It's no surprise they act differently with regard to A/S.

"As soon as I think I'm out, they pull me back in..." (Michael Corleone)
Doug, I think the genesis of the skating force is a bit more complex than simply that of a force pulling the stylus toward the center of the LP (or the spindle). Skating force is due to friction of the stylus in the groove, I think we all agree. The actual direction of the main force vector generated by friction is more toward the left rear of the turntable (exact direction depends upon headshell offset angle, and other factors like length of tonearm and position of the stylus on the LP surface). The reason we "see" it as a centripetal-ish force or a force pulling the tonearm inward in its arc, is because that is the only motion permitted by the tonearm pivot, due to tonearm stiffness. Similarly, AS force creates a vector mostly toward the outer and rear, because of headshell offset (and above). The combination of skating and AS vectors, if AS is theoretically perfectly chosen to equal skating force, would be to pull the stylus and cantilever back into the cartridge body. (Maybe that could cause the dampening to which you refer.) I think that the reason we observe bent cantilevers is that in most cases there is too much or too little AS. Anyway, that's my take on the subject. You and others have made me an AS minimalist but not a nihilist.

Yes I agree with Lewm that AS should be applied, with due care.
In my experience as a dealer and 30 years of audio I have found that very few TT's provide a platter surface and armboard surface that are congruent, that is if the platter is level then the armboard isn't. How many of you have run dial calipers over the platter/armboard to measure this and corrected it.
If you dont run a unipivot or arm that includes adjustability for levelling the horizontal bearings, then you have in inward or outward force applied to the cartridge before you even start.
It is entirely logical to me that each arm may require different AS levels due to differing arm geometry, cartridge alignment preferences and bearing friction levels.

I think the most common issues with applying AS that I have seen are :
Compensating for an out of level arm relative to platter surface.
Compensating for output level imbalances between channels, either in the cartridge or system ( or even the audiophile's ears ! ).
Following the manufacturers recommendation without listening.

I can pass on my experience with the Ikeda MC which has no cantilever. The diamond is mounted on a hoop which is at a rightangle to the groove. The hoop is held by a string which prevents the hoop from being pulled out when playing. The hoop has a little compliance built in.
http://www.avguide.com/blog/high-end-audio-japan-part-five-analog-ikeda-sound-lab
This cartridge requires AS on every tonearm I have tried it on, both unipivots and gimbal bearings. No antiscate the you get mistracking, channel imbalance and compressed soundstage and harmonic structure. Optimum AS applied yields no mistracking, no channel imbalance and most importantly maximum soundstage and harmonic structure.

Lew,

I agree with the elaborations in your post. For clarity, the only point of my (admittedly over-simplified) analogy was to illustrate this fact:
- skating forces act (first) upon the stylus
- anti-skating devices act (first) upon the tonearm

This seems non-controversial, obvious even, but this difference must be mediated somewhere. Practically speaking, the only non-rigid component between the stylus and the tonearm is the suspension in the cartridge. That's where imbalances between skating and anti-skating forces will be dampened. To the extent such dampening occurs, sonics will be affected.

Skating is a component of the force vector generated by the friction between the stylus and the vinyl. If the stylus on a pivoting tonearm is not in line with the center of the pivot bearing, then the x and y components of the friction force try to pull the stylus out of the tonearm, ie. away from the bearing and also left (towards center) of the tonearm because the stylus is to the left of the pivot bearing. Linear tracking tonearms have no anti-skating adjustment because the stylus is in-line with the sliding arm tube bearing. It has nothing to do with the grooves. The tonearm will be pulled to the center of the record even with a blank vinyl disc. Since the counter force, or anti-skating force must be applied at the pivot of the tonearm, cartridge manufacturers apply a bias or prelaod to one side of the stylus/cantilever suspension just like they apply a preload to the suspension in the vertical direction. That is so when the cartridge is cued onto the record, the VTF load and AS load center the stylus in its suspension- as long as those loads are to design intent. Try to look at the stylus cantilever on your cartridge sometime when it is in the free state. It should look offset down and left. Then cue it onto a record and it should look centered and left. Now start the record turning and it should look centered. That is if the loads are adjusted within the range of the cartridge manufactureres' specifications.