Tracking error distortion audibility

Dear All, I do agree with Raul on most of what he said in his last post.
However - let me put it in a few "axioms":

1) offset, overhang and effective length do relate to each other and CAN be CHANGED WITHOUT changing the PIVOT-BEARING DISTANCE. Offset, overhang and effective length do change when you align to a different arc-calculation (say - change from Baerwald to Loefgren).

2) If you change the pivot-bearing distance you change the WHOLE GEOMETRY of the given tonearm.

3) you get the very best results with the recommended pivot-bearing (= mounting distance as specified by the manufacturer, because the whole geometry of the given tonearm builds on that one parameter.

4) whether you choose Loefgren, Bauer, Baerwald, Stevenson or whatever calculation for the alignment of the stylus (and these calculations are onyl aiming at the position of the stylus - not at the position of the tonearm !!) is INDEPENDENT from the geometry of the tonearm itself. These alignments can all be done at the headshell alone without moving the base (and thus the pivot-bearing distance). And they should be done without moving the base because that way you can be sure that the basic geometry of your given tonearm is as specified by the manufacturer.

I think we must clearly put a line here between the geometry of the tonearm WITHOUT a cartridge. This is the basic geometry of teh tonearm itself.
Then there is teh geometry of the stylus in a given tonearm. This is step 2. Here we have the option to align to whatever calculation does fit our needs best (for instance more modern pressings with long run-out-grooves or pressings from the early 1960ies with the inner grooves running close to the label - these need different alignments - one rather Baerwald - one rather IEC). Here we lay the position of the 2 zero-error points and the maxima and minima derivation. This 2nd alignment does have variations in the offset, overhang and effective length (not much, but some) - but NOT in the pivot-bearing (mounting) distance.

Hi, just a little aside from behind the curtain as it were.

SME in their misguided wisdom using the "ICE-standard" (that strangely exists for LP manufacturing at al, BUT not cart ALIGNMENTS, correct me if I'm wrong ) for their alignment happen to use Baerwald, hallo!

Now Baerwald is what most everybody and his uncle is using these days... and is constantly being referred to in this here circle, very good.

The other item that might shine some light on this pivot to pin distance issue, and SME's disregard for such importance is: The SME V (in fact all 300 series) are based on a mounting hole to stylus tip distance of 9.52 mm or better 3/8". Therefore 233.15mm stylus-to-pivot distance, and a 23.6350 offset angle.

Most carts I've seen/worked with are ball-park, give or take 1/10 of a millimetre. This means that the post is move by about that amount to correct for overhang for that specific cart. A difference in VTF alone will change this distance by some 0.01 mm.
Nobody seems to take note here, that when a hole of some dimension about 32 mm is drilled in a plinth to take a fixed pin/pivot arm arrangement, that 1/10 mm or even less is simply within tolerance.
Unless this is done in a tool shop with a highly accurate machining set-up.
So whilst I DO agree with the importance of it all, I surely disagree to get complete anal about this. Reality of arm fitment is most probably a lot worse than <0.1 mm.

Now I feel so much better :-)
Greetings,
Axel

Dear Axel: Certainly the analog imperfect world " permit " that the people take decisions that are more oriented in " feelings " than in scientific care like the tonearm/cartridge set-up. Even those 0.1mm affect/provoke changes/distortions that are added at the whole audio system ones.

This kind of " behavior " unfortunately happen in every single link in the audio chain, sometimes by careless and sometimes by low know-how.

What is important to note is that many of those distortions are in our each one " hands " to make it lower if we take care on it not only in the whole system set-up but in the whole audio item system selection.

There are many many different subjects/factors that are "under " our each one control but even we don't know it.

Our each one audio learning curve is a " long road to home " journey where maybe the best way to help us is through an open attitude thinking that almost always exist a better " way " to make things to improve/grow-up.

I always try to think that the " best " is for coming.

Regards and enjoy the music.
Raul.

Dear Axel,
the SME 300 series is one of the very few tonearms which does come with a kind of "fixed" geometry in ALL parameters. Given its unability to adjust offset, overhang (we can just move the base - which we shouldn't... - NOT the cartridge ) and effective length, it surely is a fairly unique sample.

SME took for granted all industry standards of its day (early 1980ies) and said:

"well, if all cartridge designers do obey to and follow the standards given and if all LPs are cut following the new IEC standard, then evrything will be perfect with our new tonearm - it will be the "best tonearm in the world"............"

But the world is an imperfect one and many people do want to go their own ways.

The new SME surely was the LEAST UNIVERSAL tonearm ever designed .......
It is for sure the one tonearm which gives almost no possibilities to adjust to specific cartridge needs or to different arcs.

The SME V was a child of its day and was regarded when introduced as the first tonearm which took all (some fairly new...) industry standards for record-cutting and cartridge dimensions serious.
Too serious.

In a biological sense the SME V is the very opposite of evolutionary versatile.
It can not "adjust" to any change in the "enviromental conditions".
With the "right" cartridge, it is a VERY serious tonearm.
But there are so very few "right" cartridges for the SME V around.......

Dear Raul,
yes, the analog world is an imperfect one and will always be.
I just think that in tose few areas where we do have pure sientific parameters - teh geometry - we should try to use them for the very best results and should follow them as strictly as possible.
There are so many other segments of the analog front-end, where our "feel" and "intuition" is of paramount importance - cartridge, cables, VTA, VTF etc.
Here however, pure geometry is I believe of great help.
This is the reason why I permanently insist on the strict application of the 2 geometrical calculations for the complex tonearm/cartridge topic.

Its the foundation of all which follows in the audio chain.

Making any mistake here, will make it VERY hard - if not impossible - to fix that "bug" ever after.