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Will SME-V, etc benefit with non-stock alignment?

Hi,
it was suggested by some most knowledgeable member(s) on the subject of tone-arm alignment, to start a dedicated thread for 'fixed' stylus-to-pivot measurement arms.

To my knowledge those would be ALL SME arms, as well as ALL Linn arms -- there might be others.

The issue in particular is the method of overhang adjustment by moving the pivot (bearing arm post) a la SME to accommodate slight variations in cart design. Linn does not even offer that (go buy their cart(s), and get a life :-)

In the case of SME, the expected mounting hole to stylus tip distance being 3/8" or in more 'current metrics' 9.52 mm. (sorry not US quite as yet, i.e. both are valid)

If a cart has this design criteria, AS WELL AS! the cantilever in the centre AND STRAIGHT with respect to the cart body / mounting screw holes, and more recently all with a tapped thread in it, they would HIGHLY qualify, or?
BUT, how do you see, or know this is the case in the first place, when purchasing a cart?

Given ALL is right-on within spec. you then are 'stuck' with the alignment that, e.g. was decided (for you the purchaser).
As soon as you'd like to try some other alignment scheme, and there are some: Löfgren A (Baerwald) -- the SME point of view/choice, Löfgren B, Stevenson, plus in fact you may make up your own, that may be to your liking. BUT NOT with any of the 'fixed' type arms, since it'll play havoc with the arms intended alignment geometry. (Ask DerTonearm if you don't believe me. He'll give you the low-down right to the 100th of a millimetre!)

So far, so good. You can go to one of the expert template makers, state your case, give your cart and arm parameters and ask him to make on for you. 100$ ---- to 500$? somewhere around there.
BUT WICH alignment then please?!

One you think is better? The same? Why bother for the same?!
And IF different, will it actually work for you?

Well, if not, go spend some more 'greens' on the next try?

Of course if you are aware of these issue, you just go and buy another arm, right?
Hallo, but what about synergy for SME decks, ditto Linn decks and arms?

So hope to have made the point sufficiently clear. So let's see what we can learn, that we do NOT know as yet.
Could get interesting, I hope so.

But please keep it informative and don't come tell us a dentists drill will be a better choice than XYZ tonearm choice.
Thank you for reading,
Axel
axelwahl
axelwahl OP
788 posts
 
Hi Jonathan,
GREAT post, thank you!
Hell, and I just had though my thread's gone stone dead.

You mention the rubber damper, I guess it's what some older folks call the 'gummi' right?

If that is so, than there is that other item, 'Spanndraht' tension wire? , which more than anything else seems to contribute to compliance, if you can confirm this.

Still with the damping, there is as always yet more. I think of Ortofon's 'mixed bag of gummi, gold and what not flux-damping rings --- and the more obvious flux-damping coils on Dynavectors V flux bracket, yes?

Now, why I ask this is related to the effect(s) of these. Your Dorian, is very 'open' and with exemplary channel balance -- BUT it goes 'dilly' past 10kHz and needs some good old down-loading i.e. to 'clamp it down' before it goes screaming at you. No fux damping here by design choise, yes?

So, no way of running this cart into 47k i.e. un-loaded.

Now we look at the other two mentioned, using flux-damping, they perform jolly nicely into 47k.

And here's the kicker, a statement by some guru: "The better the cart, the less loading it needs." That so?

Would be nice to get your take on this, plus to correct some possible misconceptions on my side. No harm done, promised.

Greetings,
Axel
rauliruegas
13,125 posts
 
Dear Jonathan: Thank you for your explanation. The whole subject is try to find a " number " to be a standard but I can see is very complex.

Regards and enjoy the music.
Raul.
berlinta
104 posts
 
Hi Jonathan,

For a start, please check out:

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1235522919&openflup&128&4#128

You wrote:
"One thing that I haven't seen yet in these threads is an effort to _quantify_ the change in distortion that will occur if a cartridge is not precisely 9.52mm, what happens to the distortion if the base is shifted backwards (assuming an SME), how much the headshell offset angle needs to be changed to compensate, and how much slack you need between the headshell screwholes and mounting screws to accomplish the requisite change in offset angle. Cartridge alignment is never going to be perfect - for example a Baerwald alignment only results in zero tracking distortion at two tiny places over a span of 100mm or so. If we are going to talk about distortion, at least let us try to first quantify it, and then we can decide for ourselves if the level of distortion is acceptable or not."

If you define the amount of displacement, I'll gladly provide the measurements for the resulting changes: Null points, max. or specific distorsion for any r.

As you said, any alignment method worth considering will result in two Null points. The location of those will determine the distorsion magnitude at the error maxima.
In a previous post(different, but related thread) I asked what the threshold of tracing error related distorsions was(how far can we deviate from tangency before the distorsion becomes audible?). Off course there was no reply as this is largely dependent upon the individual(its tolerance to such distorsions) and the resolving power of the replay system.

What hasn't been addressed is the question whether different stylus profiles cause a difference in the magnitude and in the makeup(even/odd order harmonics) of those distorsions.

More specifically: Will a line contact stylus equipped cartridge produce less objectionable distorsions than, say, an otherwise identical one with a spherical stylus for the same alignment deviation from tangency in degrees and position on the record expressed as r ?

I realize that it makes limited sense only to produce identical cartridges with different stylii, when ideally a change of stylus profile requires other design changes(suspension etc.) as well.

Time to hit the sack...

All the best,

Frank Schröder
axelwahl OP
788 posts
 
Hallo Frank,

you say:

>>> What hasn't been addressed is the question whether different stylus profiles cause a difference in the magnitude and in the makeup(even/odd order harmonics) of those distortions. <<<

It is ECAXTLY because of this question, that I'd started the thread: "Influence of stylus shapes on distortion"

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1241351600&openusid&zzAxelwahl&4&&

It has as background the notion, that even such 'old' stylus shapes like 'round' or 'elliptical' have still their following. They seem to trade a little less detail, for less 'unpleasant' if not truly LESS distortion.

To clear up this often held misunderstanding once more :
"Other than at the two null-points (where ever they are, due to Baerwald A, B, Stevenson, YOUR OWN flavour!, etc.) there is always DISTORTION. This can be seen on the various 'arc/distortion' graphs produced by these alignments.

Frank, I think your question about the HARMONICS related to these inevitable distortion is where such inquiry aught to be headed.
If a round or elliptical shape will produce more even-order, less odd-order harmonics AND we can somehow prove that, it will be of GREAT help and inside, I think.

Thank you, for your most valuable input --- but shouldn’t we move this over to the dedicated thread as pointed out above?

Greetings,
Axel
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