Dr. Feickert Protractor

@lewm : Here an answer on what you ask. I took a 265 mm. tonearm effective length and compare LÖfgren B vs Stevenson.

https://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=el&a1lv=265&a...


You can see that only very very near the most inner groove Stevenson has lower distortion level vs Löfgren B : this is between 65.5mm and 60mm in the LP surface.
Löfgren is the curve in red and Stevenson in green color.

R.

Raul, can you give an example of (one) lp, that may be known to most of us, that you use to explain your views?

In fact, I cannot think of , ever, you have posted your experiences with a certain lp.

Please give us an example of your ongoing remarks that can be observed by us all, in a musical recommendation. Thank you!

I want to believe? It's up to you now.

Baerwald and Lofgren made their fundamental publications in the first half of 20th century. Later in the early 60s Stevenson (another mathematician) has calculated a new set of parameters taking into account that on records with classical music very often crescendos occur towards the innermost grooves! That make sence.

The key word for Stevenson is "crescendo" which is a passage played with a gradual increase in volume or intensity (in classical music). According to Stevenson's alignment method a new set of parameters taking into account that on records with classical music very often crescendos occur towards the innermost grooves.

It's about arrangment of the classical music and where is the most complicated grooves located on the record surface (beggining, middle or toward the end on the record). It can be true if we are listening to a long (17 min for example) classical music track on 12'inch or 10'inch (or even a short 3 min track on 7'inch record).

A crescendo is a way for composers to indicate that a passage of music should gradually increase in loudness over time (opposite of a decrease in volume which is described as a 'decrescendo'). It is also used in non-musical context to describe any situation in which volume is increasing.

BTW the most complicated grooves with cannon shots on Telarc 1812 Overture located in the end of the LP.

I not listen to classical music at all, but i do listen to 7'inch records (along with LPs) and for small size of the 7'inch where all information located close to the inner groove Stevenson is theoretically is optimal. But i do not hear any distortion if i play them with Baerwald, so my point is "theoretically".  

OP,

After that little trip down the rabbit hole courtesy of Raul, maybe we can get back to your topic.

I use the Acoustical Systems SMARTractor, (https://www.arche-headshell.de/alignment-tools/smartractor/)which is similar to the Dr. Feickert protractor. The difference between these tools and a paper protractor is not the accuracy, but the ability to perform your alignment in a more accurate way. IMO these protractors allow you to see the alignment better, and because of that you can achieve better precision.

The Mint protractor, which I have also used, is designed to be used for a particular brand and model of tonearm. If you have different tonearms you need a different protractor for each different tonearm. A great tool if you only have or will have one tonearm.

I also have an alignment block similar to the one referenced by rsf507. IMO also a great tool and worth owning.

Best Regards,

Jim Perry

Dear @slaw : There are several LP’s that comes with dificult grooves to track NOT ONLY at the very inner grooves ( last 5-6mm ) where we can listenig using Löfgren A or B vs Stevenson.

Example: the Reference Recording Symphonic Dances comes with those " cresendos " way before the middle of the LP, Refrenece Recording Dafos ( Gate of Dafos track. ) almost the same: first part of the LP surface.
Mercury Firebird with the big drum attack at the middle. Reference Recording Berlioz Symphonie Fantastique where the high velocity recorded grooves are at the end but at the middle too.
The Telarc 1812 has not dificult recorded grooves at the inner grooves ( last 5-6mmm that’s where <<stevenson " works " ), it has several passages all over the LP surface.
Pictures at an exibition or Nigth Bald Mountain st several passages recorded at high velocities and not necessary in the low bass range.

As a fact exist several recordings where the hard task comes with mid and high frequency ranges at different LP surface areas. Many piano LPs recordings are dificult to track it and produce high distortions.

Now, when the cartridge/tonearm has dificult to track some LP grooves and these are at the inner grooves what we can do to find out which the problem we need to make this test ( obviously that the TT/cartridge/tonearm set up must be accurated. ): we listen to the LP in normal condition ( all the LP. ) after the side finished we clean perfectly the LP and the stylus tip and listen again only to those inner grooves and normally the tracking improves with lower distortion levels.

Why normally those happens?, well even if we can’t see any sign of dust in the stylus tip after only one LP side exist microscopic dust accumulated down there and this very tiny quantity of dust goes against the tracking abilities of the cartridge especially in the high velocities recorded grooves an increment distortion levels.

High velocities recorded grooves are hard to track it does not matters at what place in the LP surface. As I said piano can gives problems but trumpet or other " easy " instruments different of drums/percussions/organ makes its " job " challenging the cartridge rides. It does not matters either the kind of alignment choosed.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.