Uni-Protractor Set tonearm alignment

Raul,

After this explanation, I am going to have to give up on this. I will stipulate that all the numbers you have provided above are correct. No dispute there.

I tested the original claim from many months ago (with an estimate I have labelled Dert63 above) against the original reference (245mm EL Baerwald or Lofgren). One does not, in fact, have to compare everything on a common P2S or common EL because in fact, the original claim did not.

In this thread, he made certain VERY specific and precisely qualified claims. Those claims were VERY clearly made on the basis of a certain opinion about record size (hence my use of DIN standard) and his own listening priorities (reduce distortion in the latter half of the record at the expense higher max distortion at the beginning), i.e. use a weighted distortion curve rather than an un-weighted distortion curve. Again you ask for proof. He wouldn't provide it, for what I now clearly see were good reasons not to, but I was curious, so I derived what I could based on these claims. As I have shown, each one of the claims seems to hold up when one does the math.

To my knowledge, NOBODY (not myself, Dertonarm, or anyone else) has EVER disputed the 'fact' that over a whole record, Lofgren B and Baerwald/LofA have lower average and lower equal-peak un-weighted tracking distortions than any other solutions for a given effective length. It is just math. Everyone stipulated this point long ago. Just to be safe, I repeated it.

His opinion about the qualitative aspect of tracking distortion across the record is clear. His listening priorities are clear. Based on his 'weighting', he has recommended and used something else than standard. That is his choice. As 'proven', his priorities would absolutely support use of Dert63 vs either of the Lofgrens. As you said, there are no 'absolutes' other than the math. It is some people's opinion that 'math' can be absolutely perfect in theory, and still applied wrongly sometimes.

The math stands up to support his priorities. The math stands up to support your priorities too. Everyone needs to make their own choices about priorities. I leave it there.

Kudos to Dertonarm for staying out of this. I should have as well.

Dear Pryso, no problem. My "question" was rather ironic and could easily lead to a misunderstanding. Mea culpa.
Cheers,
D.

Dear Nandric, dear T_bone, I discussed the FR-64s alignment parameters briefly with Klaus Renner (founder and editor of DAS OHR who sadly passed away while still in his thirties in 1991/2) in the mid-1980ies.
Based on initial proposals of A. Wagner/Munich.
In the early 1990ies - long before there was a VE-calculator on the web (heck - the web weren't really there back then (at least not in the sense we see it today)!!) - I calculated it a more in-deep and extensive.
On white sheets of paper with a pen, ruler and a pair of compasses ...... archaic today.
Anyway - I do not want to lecture anyone nor do I say that everyone has to follow my proposal or idea regarding the FR-64s tonearm.
It is a proposal, it suits my needs, allows the FR-64s to show it's virtues and to my knowledge has never failed to sonically impress a FR-64s-owner once he tried it.
When I give a proposal in audio is is based on my experience, proofed it's merit, is most likely at least worth a try and generally not a balloon.
That I like to go different ways should not disqualify me from the start.
So far and where I live this is a free world (so far and in some parts ...) and everyone can choose what he/she/it likes best.
Former Prussian king Friedrich "the great" put it very nicely more than 220 years ago: "Ein jeder werde selig nach seiner Facon!".
Cheers,
D.

Thanks D. I think I can see why people would like it. And I agree - all it has to do is suit one's needs and work well, and it would seem to be a better solution than the template provided with the arm. It is good to be open-minded about one's own priorities and be able to question the 'establishment' standards, even if it makes you a criminal in the minds of the 'authorities' or the moral police... :^)

Dear T_bone: I hope that with this post I can finish my intervention on this regard.

IMHO all these numbers/calculations for geometry cartridge/tonearm set up is in many ways something " academic " and very informative for the best part.

I already posted but maybe you or other persons don't remember:

++++++ " But I don't finish yet, we have to take in count too the LP characteristics and characteristics on was is recorded there: off-center LP hole, waves all over the LP, different recorded velocities at different areas in the LP surface, thickness of the LP, resonance of the LP build material, etc, etc..
These LP characteristics has an influence too in the cartridge quality performance. " ++++++

all our discussion on the subject about numbers are on static cartridge/tonearm status with no single sound in our ears coming from the speakers.

All those distortion level numbers prevail on dynamic cartridge/tonearm/LP motion/playback? , IMHO did not.

Now, imagine just for a moment what happen when an audiophile likes to be anal about SRA/Azymuth/VTF ( that I insist IMHO are a little more critical and important that that geometry set up for the " Mercurys ". ) set up on motion/playback and he changed all or one of these parameters with any single recording he is listening ( for whatever reasons you could think. ).

Any single change on SRA/VTF ( between other changes in set up cartridge parameters as LP off-center hole or LP waves/non-flat surface, etc, etc. ) change the position of the cartridge stylus tip and if he/we want to stay 100% accurate with the set up cartridge/tonearm numbers calculated he need to re-set this geometry set up each time he makes changes on those other cartridge set up parameters!!!!!, " crazy " don't you think?. Whom will take care about and why?.

As some one posted here: " we are to enjoy listening music " and not for changing ones and again the geometry set up cartridge/tonearm each time we change SRA/AZ/VTF with new calculations!!

That's why I said all that is in some ways: academic and informative.

That's why almost all of us made cartridge SRA/Azymuth/VTF set up by " ears " and this means on: motion/playback status.

We can´t have " absolute " control in our beloved extremely imperfect analog world named: LP. Each one of us according each one priorities and knowledge level made and make the best we " have on hand ".

regards and enjoy the music,
Raul.