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

Axel,
My answer is YES. The MINT Tractor was a big improvement over my stock SME protractor. Once I supplied Yip with my exact cartridge specs (stylus tip to mounting hole distance) he made a protactor for my specific cartridge/arm combination. I found that my overhang was off by about 1.5mm and zenith or offset angle was off by a couple of degrees. There is no way to accurately confirm offset angle with the SME tools, but it is very easy to align the cantilever with the parallel lines on the MINT tractor and rotate the cartridge until everything is correct at the null points. The sound of my system improved considerably, and I assume that it is because the cartridge is better aligned and now I hear less distortion. The cost of $110.00 was easily worth it for me.

Raul: Yes, I think that to insist on 9.52 would be a severe limitation on cartridge designers. I can easily envision configurations which would tend to be shorter than 9.52, and I can envision configurations which would tend to be longer, too. Of course, if cartridge designers all avoided architectural diversity and only used configurations which fit into the 9~10mm range, 9.52mm would be OK (grin).

One other major variable is the rubber damper systems used in most cartridges. In the small sizes used in cartridges, rubber is not a very consistent material. The characteristic that you are looking for primarily from a damper is consistent damping behavior, but due to the variable nature of the material, consistent damping behavior is not the same thing as consistent thickness, or even consistent pressure. When I was just starting out in cartridge design and still inexperienced, I thought that a consistent pressure system would be perfect for adjusting the dampers and suspension, and would make a major step towards consistent dimensions. So I designed a calibrated adjustable weight system to apply consistent pressure to the dampers and suspension during the building process, and instructed a batch of cartridges to be built like this. The dimensions were fairly consistent (albeit not absolutely so). However, the performance measurements were all over the place, really bad, and that batch of cartridges needed to be built again.

I learned the hard way that each damper is unique, it is better to let a trained and experienced cartridge craftsman adjust the dampers individually, and accept whatever dimensions that arise from this.

You can, of course, prioritize consistent dimensions (like I did decades ago), but most likely you will find that the cure leads to worse diseases in other areas.

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.

FWIW, also note that some other tonearms with fixed screwhole headshells, like the Naim Aro, appear to have been designed with a much shorter cartridge in mind, From what I can tell, these were designed for cartridges of 7.5mm or 7mm pitch. The same applies to the Linn arms, if you use the third hole.

cheers!

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

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.

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