Why use a super accurate cartridge protractor

Dear Nikola,

I find it harder to see (and hear) things as time marches on. But I try.

As you say, the protractor is only as good as the widest tolerance. Which is my point. As DT says, spindles vary, by 0.25mm. So there we actually have a number. But he asks

Why use a super accurate protractor?
Simply because it helps to get the best (read: best sonic performance) out of your cartridge/tonearm.

So super accurate means that "best" is sonic performance, as opposed to physical performance.

In other words to continue DT's analogy, if Michael Schumacher could drive his Ferrari with the old beetle tyres faster than Dertonarm using the expensive ones, then are his tyres better than DT's? Would we buy them?

Wouldn't we rather look at the description of the tyre's performance? The reasons we might choose it for a Ferrari, why it might be suitable.

The analogy here is to the protractor's performance. How accurately can it set up the arm. Will it be within 1mm, 0.5mm, 0.1mm in overhang? Will it be within 1degree, or 0.5, or 0.1? Mounting distance? And how repeatable is it?

I'm not saying Dertonearm's protractor isn't precisely made, or can't give good results, just that neither he, nor anyone else, gives a specification for protractors, one of the few areas in hifi where that is the case. If it was an amp, would manufacturers get away with saying how loud it goes depends on how well you set the volume control?

Perhaps if someone said it was precisely made? Or said it looked impressive?
Or maybe I'm getting too old and too cynical.

John
.

Dear John, 'Too old'? What a pity. I think you could be a very good teacher. The persons who know what they are tolking about and have clear thoughts are usualy able to
express them clearly. On the other hand I think that skepticism has more to do with the social enviroment then knowledge.
We are glad to have you and Dertonarm as our members.

Kind regards,

Dertonarm

I hope you have an enjoyable holiday, and, of course I agree with you that everyone should choose their alignment according to their record collection - would that were always the case. And for your collection you have chosen correctly. We have never disagreed on that.

Now on to other matters, and perhaps I shall manage a holiday at some point, though some would say, though I'd disagree, that I treat all my life as a holiday.
Regards,
John

Hi John_Gordon -
Interesting you should mention offset angle. One of the strengths of the Phantom jig is angular alignment of the stylus/generator.
It's an old article I know, but it stuck in my mind because of it's relevance. Scroll down the link to "The Need For Precise Setup":-

http://www.positive-feedback.com/pfbackissues/0605/gordon.tonearm.6n5.html

The author's results were very thought provoking....

Protractors are great for aligning horizontal azimuth and effective length with any precision for a given SRA/VTA range. Vertical azimuth, SRA/VTA, and VTF are usually adjusted by ear. Although we can set AZ by eye, that doesn't necessarily equate to the best and usually takes final tuning by ear. In other words, the use of a protractor is only part of the alignment process. My 2 cents worth.

A note. MintLP Best Tractor is accurate to the 2nd digit of a millimeter. It is simply a more precisely printed loefgren A, arc protractor with the added benefit of parallax effect for sighting. Assuming one has the optics and eyesight to use it properly, it allows for alignment of the stylus, not just the cartridge body.