Is tonearm bias a compromise, maybe a myth?

I was really surprised at how much more depth there was to the soundstage and greater subtle details. I was then gobsmacked by the discovery that I had forgotten to re-attach the bias weight thread! Applying Lateral Bias seems to compromise performance elsewhere, true?

Very true, as Harry at VPI has always maintained and as I and others have described here many times. Pre-loading the cantilever by pressuring it against the elastic suspension reduces its freedom to respond to groove transients. Result? Reduced dynamics and smothering of lower level details... just as you described.

Congratulations on making the discovery for yourself... a perfect example of what I and many others have always maintained: fine tune your setup with the instrument that really matters, your ears!

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AS is a compromise because the amount of skating force your stylus sees at any given moment is constantly changing. There can be no "perfect" setting and chasing after one, by whatever method, is a quest without a destination.

For example, setting AS with a test track optimizes the rig for playing that test track. That's ideal, if that's all you play. As soon as you play music the conditions the stylus sees are different, the amount of skating force it sees is different and that "tested perfect" AS setting just became irrelevant.

The best record for adjusting AS is the one you're listening to. With some carts when listening critically I've adjusted AS from one LP to the next. Fortunately, my present carts sound best with no AS at all, so that's how I play. But YMMV applies here more than almost anywhere in audio.

Keep playin'! Keep learnin'!

"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).

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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.

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.