Help me understand cartridge alignment

Dear @lewm  : "" except everyone equates tracking angle error (the degrees by which the cantilever is not tangent to the groove) with “distortion”.  ""

Everyone but you? then you are just wrong. Which's your take?

I give you these measured examples in a 250mm EL pivoted tonearm Löfgren A IEC where is clear that as tracking error goes down as traking distortion goes down too as the cartridge is aproaching a null point or goes higher as the cartridge goes away of a null point:

at 66mm groove radius tracking error is zero and tracking distortion is 0.0001%

at 70mm tracking error is -0.359 and tracking distortion is 0.256%

at 90mm tracking error is -1.014 and tracking distortion ism 0.563%

at 115mm tracking error is -0.310 and tracking distortion is 0.135%

The measures was made at each mm and has a linear relationship between both calculated parameters.

R.

I think the arm must be off somehow. I've explored every option. Tomorrow I'm going to adjust the PTS by 2.5mm (I measure today) so an SPU will hit Baerwald exactly.

Raul, I just saw your post. What is "tracking distortion"? Are you talking about harmonic distortion, IM distortion, or what? Can you refer me to the source of your data, or have you yourself made these measurements? I am certainly willing to believe there is a relationship between tracking angle error and distortion of some kind, but I have not seen the data, until now possibly. My private hypothesis is that stylus overhang and headshell offset angle taken together are examples of the cure (for TAE) being worse than the disease. Invented 80 years ago by a few guys, who were more mathematicians than audio engineers, to drive us crazy. I realize that my view is not the norm, so I am not anxious to argue about it. But tell me how "tracking distortion" was measured, please. And thanks.

Dear @lewm  : Were measured through the Löfgren A-B equations in reference to cartridge/tonearm alignment and under IEC, DIN or JIS standards.

This is not new and this is not the first time I posted.

" is that stylus overhang and headshell offset angle taken together are examples of the cure (for TAE) being worse than the disease. "  , probably you are rigth but where are those alignment equations that proved it, at least Löfgren did it.

I think in the last 15 years you are sticked to your opinion and nothing wrong with that but I wonder why after 15 years you just has a " wondering " instead to have the maths that proved.

R.

You are wrong about my "opinion". For most of my audiophile life, I went along with the idea that very precise alignment is important. Only in the last few years have I begun to seriously question that proposition. And the key word is "question". I am not about to say that alignment is NOT important. And I do align my cartridges carefully. But I don’t fret over a mm or 2, just because of my own experience with underhung tonearms and the fact that once or twice I have discovered that my alignment of overhung tonearms was way off (only because I periodically check with a protractor) without any audible associated deficit in SQ. This may be because, even based on your own data above, the associated distortion (which I still do not understand the nature of) is low compared to the sum total of all the other distortions associated with vinyl.

The reason I am still in the dark as to the nature of the distortion associated with minor misalignment of an overhung cartridge is that your response, "Were measured through the Löfgren A-B equations in reference to cartridge/tonearm alignment and under IEC, DIN or JIS standards." suggests to me that you misunderstood my question or I misunderstand your response. Do you mean to say that (someone) measured actual distortion of the audio signal in relation to IEC, DIN, or JIS standards?  If that is what you mean to say, what sort of distortion was being measured?  To say the standards used is not to describe the nature of the distortion.  What I am asking cannot be answered by any equation, because an equation will give you a theoretical answer only, and my real question is whether reality conforms to theory.  Lofgren, Baerwald, and maybe even Stevenson all did their work around 1940, so far as I can find out.  Way before stereo or any high fidelity home audio.