1. SKATING FORCES EXIST
If a tonearm of fixed length (1) pivots around a fixed point and (2) has an offset headshell, then it will generate skating forces whenever the stylus is riding a moving surface. Whether the tonearm uses a unipivot bearing or some other style of bearing is irrelevant. This is non-controversial, as it's based on irrefutable laws of physics.
2. CORRECTING FOR SKATING FORCES MAY INVOLVE COMPROMISE
Whether such skating forces should be countered by some gizmo that applies a (roughly) counteracting force is a matter of debate. The factors to be considered have been mentioned:
- risk of uneven stylus wear
- risk of uneven record groove wear
- effect on sonics
My own experience is that anti-skating devices have a deleterious effect on sonics. This is a personal judgement based on my system, using my ears. If you have a different (or even opposite) experience we have no disagreement, just different systems or sensibilities.
Those like Stringreen, Dopogue and I who hear negative sonic effects from A/S gizmos must make a decision. We don't question the risk of uneven stylus or record wear. We do have to weigh those risks against the increased sonic/musical enjoyment we experience from accepting them. My choice, like theirs, has been to increase the enjoyment and accept the risks. In my case, I've gone so far as to remove the A/S gizmo from my tonearm altogether. Doing so provided additional sonic benefits, since it removed one more source of stray vibration storage/feedback from the system.
You may make a different choice based on different sensibilities and/or different priorities. Your choice will be as valid for you as mine is for me.
3. ADJUSTING THE ANTI-SKATING GIZMO
If one does choose to use an A/S gizmo, the method which makes the most sense is to adjust it while listening to the music you typically play. As noted above, skating forces generated by a blank side or by some test track bear little relation to the skating forces generated by musical signals on real LPs. Blank vinyl or test tracks only optimize A/S for blank vinyl or the test track. The moment you cue up a real record, an artificially calibrated optimization goes out the window.
4. WHAT PETER LEDERMAN DOES
Appeals to Peter Lederman's recommended blank disk method based only on his status as an equipment designer/rebuilder, amount to the logical fallacy known as an "appeal to authority". Appeals to authority fail to address the substance of the question and therefore neither prove nor dis-prove the position. In logic, an appeal to authority is irrelevant.
One could just as easily point to Harry Weisfeld's preference NOT to include an A/S gizmo. HW has designed, built and rebuilt at least as many audio toys as PL, so his authority is no less. By itself, this would also amount to an appeal to authority and would be no more valid.
What distinguishes HW's recommendation from the PL recommendation stated above is that we know HW's reasons: he prefers the sonics of his tonearms with no A/S gizmo (rather like Stringreen, Dopogue and I). That's a valid argument because it addresses the core questions of risk vs. reward. It's also a personal value judgement, as valid as mine or yours, but neither more nor less.
For PL's reported bland disk recommendation to be relevant, we would need to know his reasons for believing it to be correct or useful. Lacking that, we know nothing of value.
On supposition, one suspects PL has had anecdotal success using the blank disc method as an approximation. It's unlikely to be more, as there is little correlation between the friction between a stylus tip and a flat surface and the friction of the stylus sides with a highly modulated groove.
