Yes, it's confusing, but I was talking about vertical and horizontal motion, not vertical and horizontal bearings. You said
But if the pivot is appreciably higher than the record itself, there will be increased vertical arm motion (rising and falling) proportional to the distance of the pivot above the record.
but this is identical regardless of the height of the arm bearing. What the good Doctor describes, correctly in my view, is that increased bearing height causes the stylus to undergo a fore-and-aft horizontal movement over warps in addition to the vertical one, and this causes variations in the speed of groove tracing, aka warp wow. The result is the same as wow in the platter's speed.
I see that what I wrote was not what I meant to write, because Pramanik was referencing warps and I did not include that, which I should have. For that omission, as they say in Chinese period costume dramas, "I deserve to die a thousand deaths."
We can say that with a perfectly flat record there will be no vertical (up and down) movement of the pivot, regardless of its height in relation to the record. With warps, however, the higher the pivot is from the warp will have the effect of inreasing and decreasing VTF (vertical tracking force) as the stylus traverses the warp. Thus, placing the up and down pivot (what Pramanik calls the horizontal pivot) at the level of the warp will result in a more stable system, all other things being equal (more on that later).
Lateral (horizontal--side to side) movement of the arm is possible if the record is eccentric, causing "an outward motion of the tonearm for every half-rotation... On the other half-rotation the inward motion will be larger by the amount of eccentricity. Bearing friction will have the same effect, but the increase and decrease in contact pressure will alternate between groove walls."
The obvious question is audibility. None of these effects can be singularly discussed much in isolation from the rest of them, as we are looking at a 'system'. Also, a lot of the effects can be measured, but not readily heard. In one of Dr. Rich's excellent cartridge reviews he states that he was unable to 'hear' the effects of mistracking on the test record, but was able to 'see' effects in the form of distortion, on his 'scope.
In my experience, FWIW, the only two major determinants I've come across that I believe I can reliably hear as I make changes are a) lateral tracking error and b) vertical tracking force differences. I can't reliably claim that I've heard differences when changing anti-skating, or even cutting it out. I should mention that I'm talking systems where things are relatively stable. Obviously one will have poor results if cartridge compliance parameters do not match those of the tonearm, and major resonances happen.
In a way, the thing with records is that absolute fidelity is typically average to low, and there are so many variables (most not user adjustable) that it is easy to get bogged down on details that may or may not matter, given the final sonic product. Also, changing one setting likely affects another, so you have to consider 'trade offs'. All of that could be what makes it a 'fun' hobby--i.e., it is so interactive. But it is also likely why many just 'chunk it' and go with something easy and technically better--i.e., digits.
