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
May I jump in here to give an honour mention to the excellent and easy to use Graham cartridge alignment device that always is spot on with any cartridge I mounted, doubled checked carefuly with two points protractors. This clever device is a pleasure to use because you know alignment is correct BEFORE the armwand is mounted on the arm. I wish that all tonearm designer include this kind of device with their tonearm. It is safer for our valuable cartridges.
I read the thread about Mint protractor and noticed that some Graham alignment gauge users find differences in alignment. In my experience there are differences from one to another, some have some "play" in the foldable plastic device , other not. I had to return 3 to have a good one with no "play", and here I have no error anymore. I don't say it is the ideal and absolutely perfect way to cartridge alignment but a smart and SAFE way and certainly an idea to perfect for the future tonearm designers.
Dear Jloveys, agreed. Bob Graham is one of the - very few... - who has done literally all his homework. His tonearms are - in the very sense of the word - "complete". With his clever pre-set-up alignment he provides a tool which will enable even the most inexperienced audiophile to get at least 90% of the posible optimum from his tonearm/cartridge-combination. All you need it that and the 100% precise spindle-bearing-mounting distance (he supplys a very nive tool for that too....) - then follow the manufacturers recommendations in terms of VTF of the given cartridge (during break-in close to the maximum recommended VTF...) and that will ensure that inner goove distortion and big sonic advantage at zero-error points won't haunt you at all.

High-end can be easy......... clever applied and precisely followed physics do help a lot.
Dear Axel: Yesterday an audio friend call me to meet one of his friends ( new person for me ) at this friend place.

Well, he has a SME-30 wth the V and Windfeld cartridge with around 250 hours and he loaded at 180 Ohms ( no SUT ). We were hearing dfferent recordings and can't hear any inner groove distortion.
He was running the V in its original dinamically way and I ask to run in static way and the performance improve a little, he was satisfied.

Then, we take that Windfeld and come to my place where we try it ( loaded at 100 Ohms with no SUT ) in four different tonearms ( IV, Lustre, AT 1503 and our own design . ) where in no one show the inner distortion.

Btw, the Windfeld performs better in any of the other tonearms ( like was my experiences with LOMC Ortofon cartridges. ), in the V/IV its performance is good but not at the same level than in the other tonearms ( We try with a Nagaoka magnesium headshell and with an aluminum one, the cartridge " prefers " the aluminum one. ).

This Ortofon cartridge is very good and in some ways similar to other Ortofon MC cartridges specially the MC 7500, I like it.

Regrds and enjoy the music.
Raul.
Hey, one more thing
re: Dertonarm
--"100% precise spindle-bearing-mounting distance"--
Just PLEASE bear in mind that this is hard FIXED with ALL SME arms. Overhang is adjusted by moving the bearing-post back and forth, yes?