Geometry for pivot tonearms - calculation errors??

Dear all, The separation in 'Tonearm Geometry' and 'Setup
Geometry' as proposed by our 'new authority' in tonearm
matter, Herr Dertonarm (sorry Raul) is the subject-matter
of one article in Audio,January 1980. The authors Kessler
and Pisha ware very suprised to discover that the most
Japanese tonearms producer got the 'arm geometry' wrong
(the 'beloved' FR-64 included). Suprised because the so
called ' optimal geometry' was know since,at least,1941.
The math. was my worst subject at school and I am realy
'annoyed' to be confronted with difficult 'formulae' in
my hobby. BTW the '1mm unit' is to me the smallest I can see and handle so I have no idea how to get my stylus 'spot
on' at 66,04 mm and 120,9 mm respectively.
Herr Dertonarm is 'threaten' us with the 'fractions' of
the 'unit' mentioned and call himself a Humanist. To me
he is a direct descendant of Frege (alias 'Perfectionist').
If we intend to get this 'perfect Geometry' in reality
then the chance to end in an psychitric instition is much
much larger then to get this 'TT-tonearm-stylus' conundrum
in correspondance with the 'demands' as stated by this
German perfectionist.

Regards and enjoy the music (if you can)

Dear Nandric, many quote marks indeed........
I am constantly puzzled how many people do react so anoyed if they are confronted with the pursuit for perfection in technical parameters.
As for the FR-64s I have already made enough comments and already gave the correct and optimzed mounting distance.
Anyone NOT interested in getting the tonearm/stylus geometry as close to perfection as possible has a very good option:

in 1982 the - soon to be history again - audio CD was invented.

This was made for all those countless numbers of music connaisseurs whose smallest unit is the 1mm (which is several hundered times larger than the polished contact area of your stylus).

If you try (try....) to get the perfect geometry, you will not end in the asylum, but maybe end up with no distortion in analog playback and just the sonic results the audio press always promised you.

Leave it to try-and-error is certainly not the way to align a mechanical device.

But - sorry to have created pains in your old wounds with math (also I do not really recall having given any formulas regarding tonearm geometry - I was just displaying geometrical aspects.

BTW - Kessler and Pisha weren't all that correct in their article either and had relativeted most of their "findings" in later years.

Dear Dertonarm, My comparition with Frege was not
'accidental'. In intellectual or academic sence you can't
get a greater compliment. But even this 'greatest mind' of
Europe was 'destroyed' by his obsession with 'fundation of
math.';he never recovered from 'paradoxes' of ,say,set-
theory.
From Frege I learned not to treat 'disjunction' as 'entweder-oder' (or-or)proposition. So I am very puzzled with your statement:'Anyone NOT interested in
getting the tonearm/stylus geometry as close to perfection
as possible has a very good option: CD'.
Sorry Dertonarm but this statment is senseless to me.
Are you some kind of legislator?
I can assure you that I and others enjoy our 'imperfect'
TT-tonearm-stylys combos even if we know that thy are not
perfect. To me the quality of LP's (I own more then 3000)
is a much greater problem.
So don't get obsessed with 'theoretical matter'.
Regards,
Nandric

Dear Nandric, over the last 5 years I have mounted and aligned about 35 High-end and high-priced cartridges including Lyra Olympus, Lyra Titan and Skala, Kondo IO, Dynavector XRV-1s, Koetsu RSP and Coral Stone, Miyabi Takeda - to name just the more prominent and current ones. Tonearms included all FR-60 family, Da Vinci, Kuzma Airline and P4, Graham Phantom, Micro MAX in all incarnations, SME (all...), even Linn Ekos.

So my practical analog life has its place too aside the theoretical matters.......
The owners asked me to align their high-priced items because I am getting outstanding results in tonearm/cartridge set-up. I do so because of extreme care and because I taking all mechanical and dynamical issues into account and know how to handle them. This is a result of digesting all theoretical background, the skill to use it for practical resuklts and a lot of routine over 30 years.
I am not obssesed with theoretical matters, but I have learned to get practical real world results from digesting the theoretical background and putting all analog handwork on a very solid basis.
To math and geometry it makes no difference whether you like them or not (I didn't liked them in school either...) - the question is rather why not use them for good ?
This is no high math - its all fairly simple 2-dimensional geometry. Drawing on a sheet of paper does very likely clarifies many points - and simplifies them too - which may "sound" theoretical and abstract.
However they aren't.
Putting the mechanical foundations straight and clear just helps getting better sound.
Its that simple.
There are enough areas in our music-systems where it is MUCH more difficult to get things straight and to find the path for sonic improvement (I have built many tube amplifiers and preamps - believe me, they sometimes are a pain far beyond any problems in analog front-end).

The anaolg front-end is all mechanic and dynamic interactions.
I find it fascinating, as this is the one area where we can actually "see" whats going on and can have much more direct influence for the better than in any other part of the chain.

Thank you johnbrown and Dertonarm. Good to have more geometry delineation.
Every little bit of knowledge helps out with the puzzle.

Happy (analogue) Listening!