Is tonearm bias a compromise, maybe a myth?

Like Groucho said about Doris Day, "I knew her before she was a virgin."

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'!

Dear Lew, this has nothing to do with 'skating' but probable well with 'bias'. Groucho invented the 'principle of the variable principles' which become the principle of the American foreign policy. Groucho:" if you don't like my principles I have other ''...

Doug, I agree with your comment that one should fine tune his setup by
listening. However, there is an aspect to this that you could perhaps clarify
for me.

I am confused by what you mean by "pre-loading". "Pre-
loaded" implies to me that there is a load on the cantilever independent
of the stylus being played in the groove. This is not the case. The load is on
the arm, not the cantilever once anti skate is applied. It seems to me that
there is no load on the cantilever until it hits the groove. If the record is not
spinning, with no anti skating force, the load is only vertical if the stylus is in
the groove.

With anti skating force applied, once the stylus hits the groove, a horizontal
load then reaches the cantilever and pushes against the groove wall. If the
record is spinning an additional horizontal load occurs in the opposite
direction. I agree that these loads are constantly changing and it is difficult or
impossible to make them equal and opposite.

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."

I have tried zero and very little anti skate force on my arm and I've come to
prefer using the recommended setting from the manufacturer. I actual hear
better dynamics and more low level detail. I guess in the end, fine tuning by
listening is the best approach.

"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.