Tracking error distortion audibility


I recently unpacked my turntable from a couple of years of storage. It still sounds very good. Several times during playback of the first few albums I literally jumped from my chair to see which track was playing as it sounded so great. After a while I realized the "great" sound was always at one of the "null" points. They seem to occur at the approximately the proper place (about 125mm from spindle) and near the lead out groove. Questions:
Is this common? I have improved the resolution of my system since the table's been in storage but I don't remember hearing this before.
All others geometric sources of alignment error not defined by the null points (VTA, azimuth etc.) are essentially constant through out the arc correct? If so they should cancel out. I assume the remedy is a linear tracking arm but I am surprised at how obviously better the sound is at these two points.
Table - AR ES-1, Arm - Sumiko MMT, Cart. - Benz Glider, Pre - Audible Illusions, Speakers - Innersound electrostatic hybrid
Do linear arms really sound as good across the whole record as I hear at only the nulls with my set-up?
feathed
Dear Raul, you asked:

"Dear friends: Anyone of you can corroborate what I posted here:

www.ispexperts.com/BaerwaldLof...

Dertonarm: where can we corroborate what you posted? "

Where to corroborate my postings on this topic ?
In every decent (high-school) book about geometry........... and in the AES chronicles (but those too do demand some basic knowledge and understanding of geometry and interelations).

Regards and enjoy the music......
Dear Friends: I don't want to make this dialogue something " personal ", what Dertonarm or I think or argue about it does not matters, everything on the subject are already " say it " many years ago and the best we can do is to read on it.

Lofgren/Baerwald formulas were develped to obtain the overhang and offser angle in tonearm to " control " the tracking distortions.

Well, in those equations ( overhang/offset angle ) the parameters that they take in count are: effective length ( R or L in the equations. ) and the inner/outer groove radius. These equations have its " foundation " in those parameters not on the pivot to spindle distance.

Like I already say it:the subject is not what you say or what I say but what is wrong and what is correct.

All of us ( anyone ) can read here a very interesting analysis on the whole subject where you can find almost everything, please go to the link and there make click on Download and for the specific equations and notations ( R and L: effective length. ) go to page 30-32:

http://www.vinylengine.com/phpBB2/viewtopic.php?t=4854

I have to say that this white paper is really learning for anyone and along with the very first link ( calculator ) that I posted we can " play " to obtain amazing information on the tonearms we own and with the LP we own, like I say amazing. Now many of us can/could understand the whole subject and its implications.

Like I say in my first post in this subject a tonearm designer start/begin choosing the tonearm effective length for the design and not with the tonearm pivot to spindle distance that is only a consequence when we aply the Lofgren/Baerwald equations.

Regards and enjoy the music.
Raul.
I'm sorry, you can start reading at page 29. Well, it is worth to read all!

Regards and enjoy the music.
Raul.
Dear friends: This link that I take from other thread ( thank you Johnbrown. ) seems interesting too:

http://www.conradhoffman.com/chsw.htm

Regards and enjoy the music.
Raul.
Dear Raul, the Dennes paper is very good indeed. Its a great classic since 2 decades. However - it too does only deal with the "2nd" geometry. Baerwald, Loefgren, bauer, Stevenson etc. - this is all about the geometry of the stylus in a given tonearm. Thats why the mounting distance is not taken into consideration at all - it is not needed in those calculations and it taken as any fixed parameter.
These calculations do not deal with a specific tonearm - they deal with the ALIGNMENT OF A STYLUS in an - already mounted to its individual geometry - given tonearm. All these papers do not deal with the basic geometry of the given tonearm.

Maybe we have a big missunderstanding here - I mean there is:

A) a basic geometry of the tonearm itself. This is an individual geometry of a given tonearm.
B) then there is the geometry of the stylus in a GIVEN (= its individual geometry already fullfilled) tonearm.

This - I would like to call it "individual" or "secondary" - geometry is kind of universal. It applies to ALL cartridges and have several options to calculate and align the tracking arc and its zero-error points and maxima and minima derivations from the arc.