Dear friends: The whole cartridge/tonearm alignment subject is really important to understand it to stop that after market items follows taking advantage of our low level knowledge and I say that because that's exactly the history of after market protractors and " developed " better " kind of alignments " when in reality that does not gives true advantages.
SAT comes with its own kind of alignment, VPI the same, already looks SAEC, all japanese tonearms, uni-din and many more.
All that diversity only makes to us things more complecated when we don't understand in precise way the whole subject and we can look at the thread list in this forum and we will found out " hundred " of threads asking on that alignment subject and looking for the best.
In reality does not exist the best, in any kind of alignment exist compromises.
No one of us needs something different to Löfgren A/Baerwald or/and Löfgren B ( of course that the stupid Setevenson one is totally out of question if we are serious on the main subject and really cares about MUSIC. ). All the other alignments can't gives us a true advantage that we can detect.
Please read this where I show what is happening with tracking distortion levels inside Lófgren alignment. I took LP grooves information away of null points because as a nearer we are of null point is totally and extremelly imposible to detect any differences between recorded information in the grooves. This is only and example with a tonearm with EL 254mm.:
tracking distortion between 90mm. and 100mm ( 1cm. of LP surface recorded area. ) is 0.12%.
Maybe some of you can say: hey I can detect that tracking distortion level difference !. As I said maybe, I know I can't do it.
Now, that level of distortion is at 90mm-100mm but when playing an LP the cartridge rides the grooves with continuty: one after the next and so on.
The difference in tracking distortion level between 90mm and 91mm. is 0.008% that's the difference between: 0.553% and 0.545%.
Now, whom of you can detect 0.008% tracking distortion levels differences?. Obviously NO ONE CAN.
It's not only that the differences are so low but that the MUSIC we are listening are pércieved by us in a continue way what makes impossible to detect those kind of tracking distortion levels.
So why we oftencan post something like this: that the SAT alignment sounds better that in the same tonearm we align it with Löfgren one or uni-din or Cotter or VPI/Cotter or Clearaudio are better alignments when in reality are not.
And exist other issue when we are trying to make evaluations/comparisons between those kind of cartridge/tonearm alignments:
each time we change from one alignment to other at least we need to change the cartridge position and after that we need to res-set all cartridge/tonearm parameters: VTA/SRA, VTF, Azymuth, AS and the like and is imposible that with the new cartridge alignment the tiny stylus tip parameters will coincide with the precise and exactly same accuracy that before the change to the new alignment.
That's why I say that Löfgren A/Baerwald or/and Löfgren B is all what we need no maters what.
Don't you think? or exist something that I'm not seeing because ceratinly I can be wrong but today this is my take and invite you to think about and post your thoughts on the overall subject.
So wich protractor need we? I think that MINTLP is more than enough and with the need it accuracy for a tonearm, if we own more than one tonearm then we need additional MINTLP protractors: each for each tonearm. Why sped more money for any other protractor? makes no sense to me. Of course that we can use the self tonearm protractor if is totally accurated ( at least at the MINTLP level. ) and no Stevenson there.
Regards and enjoy the MUSIC NOT DISTORTIONS,