Remove your bias for better sound

I've always had a hard time understanding how zero anti-skating force can result in optimal sonics. It will cause the cantilever to deflect toward the outer edge of the record, as viewed from the front of the cartridge while the record is rotating. Especially (I believe) if the cartridge has relatively high compliance. How can that improve sonics? Unless:

(a)It compensates for some internal misalignment in the cartridge. Or,

(b)The cartridge is designed with the expectation that it will be used that way. Or,

(c)The arm is applying some amount of anti-skating force even when it is adjusted to zero.

Can anyone provide a technical clarification on this?

Regards,
-- Al

Almarg,

First, a correction if I may: playing with zero A/S will not cause a cantilever to deflect toward the outer edge of the record. Think about it. Groove friction pulls a cantilever along the line of its own axis (subject to minor variances in zenith alignment at any given point). Deflection of the cantilever could only occur if the tonearm resisted the inward pull of the groove. An arm with good bearings and zero A/S applied furnishes almost no resistance to the force vector created by the groove-cantilever interaction. Result: no deflection.

OTOH, playing with excessive A/S may indeed cause a deflection of the cantilever, but toward the INNER grooves, not the outer. This occurs because A/S causes the tonearm to RESIST the natural tendency of the stylus to spiral inward. The outward bias is applied to the ARM, not the cantilever. Imagine holding your stylus snug between two fingertips of your left hand whilst pulling outward on the tonearm with your right... for hundreds or thousands of hours. That's what A/S devices do, they push/pull outward on the tonearm. With the cantilever locked in the groove (your left hand) while the tonearm (your right hand) is constantly pulling outward, the cantilever is permanently pressured against its elastic suspension. That suspension may eventually take a "set", like the hole in my pillow when I wake up in the morning. That set would result in an inward-pointing cantilever.

As to sonics, I've posted many times as to why I believe zero A/S sounds best with many cartridges. Two clues:
1. re-read the paragraph immediately above, which describes what an A/S device actually does (permanently pressuriing the cantilever against the elastic suspension inside the cartridge).
2. consider that sonic penalties of excessive A/S are virtually identical to the sonic penalties of excessive VTF... diminished HFs, dimished speed, diminished air, diminished micro-dynamics, less life and zip, more weight or flab.

When the cantilver is most free to move in response to the slightest groove transient it will respond most quickly and accurately. Pre-loading the cantilever against the suspension, whether vertically with excessive VTF or laterally with excessive A/S, diminishes the cantilever's freedom to respond as quickly and completely as it might. Result: sonic dullness.

I've played with every level of A/S on my TriPlanar, from too much to the very least the doohickey is capable of to none at all. With my (mostly ZYX) cartridges, playing with none at all is the clear winner. About the only exception is some brand new cartridges, which may need a touch of A/S for best tracking until their suspensions loosen up a bit. Since my A/S device was removed long ago (with further benefits, since it's a resonance trap), I just boost VTF up a tad when breaking in a new cartridge. Not a bad practice in any event.

Other listeners have different carts or different sonic priorities, so testing for oneself is the only way to be sure what's best in one's own system.

Thanks very much, Doug. I was hoping you would bring your expertise to bear on this.

However, although my experience is limited to relatively high compliance moving magnet and moving iron cartridges, my observations have been inconsistent with your first two paragraphs. Every time I have installed a cartridge, in most cases using the Magnepan Unitrac tonearm I have had since the 1980's, I can easily vary cantilever deflection, as viewed from the front of the cartridge while the stylus is in the groove of a rotating record, both to the left (with excessive anti-skating force applied), and to the right (with little or no anti-skating force applied). This is all with respect to the angle of the cantilever when the stylus is lifted off of the record, which is nominally straight ahead.

With too little anti-skating force applied, the effect is as if skating force is acting on the tonearm, rather than on the stylus.

And what I have observed has nothing to do with the suspension taking a "set." The deflection I have seen as anti-skating force is adjusted occurs immediately and repeatably, in either direction, and occurs only when the stylus is in the groove of a rotating record.

Deflection of the cantilever could only occur if the tonearm resisted the inward pull of the groove. An arm with zero A/S applied furnishes almost no resistance to the inward path the stylus wants to follow.

I see what you are saying. Perhaps the key to reconciling all of this is how close to zero "almost no resistance" is, for the particular arm? With cartridge compliance also presumably being a factor. Although an explanation based on bearing resistance would still leave me somewhat puzzled with respect to deflection in an outward direction.

Best regards,
-- Al

This discussion reminds me of my old Thorens TD-150, no antiskating to worry about.

Most of pivot arms already have an antiskate. Try to remove the cartridge and let the arm float free. It will slowly rotate towards rest position. Applying antiskate may be necessary for the warped records or with crooked edges. I usually land the needle right on first track so don't really care about antiskate.