Technics SL1200: Baerwald or 1200 white gauge?

WARNING: Math.

Say I have a cart. It has a 10mm cantilever and a compliance of 20 um/mN. (I think these numbers are rather generously conservative; many carts will have numbers that generate even worse results than those shown below.)

Let's say that the skating force on the cartridge changes by the equivalent of 1g during playback. This isn't so hard to imagine: skating forces change drastically over the course of playback due to misalignment; antiskate calibration is known to be a little off when calibrating using torture tracks instead of real music selections; etc.

That 1g of antiskate is equivalent to 9.8mN of force. When applied to the cartridge, it deflects the cantilever by 9.8*20=196um. Compared to if no deflection occurred, this will deflect the cantilever (and therefore the cartridge) by 1.1 DEGREES. That, in the context of the ~2 degree errors present in a Baerwald alignment of a 9" arm, is huge.

I really don't think I'm exaggerating the issue. I can see my OC9 deflect visibly on a running record when I adjust the antiskate on my 1200 from 0 to 3g. Skating forces are of the same magnitude as vertical tracking forces, and they change over the course of a played record.

So even if using an inferior protractor gets me to no better than perhaps 3-4 degrees off optimal Baerwald... it doesn't matter. I'll never get it right anyway. And neither will you.

I'm not saying you shouldn't align or you should just use the Technics gague. I hate that thing just as much as the next guy. All I'm saying is that there is a tremendous amount of uncertainty inherent in the horizontal alignment of the cantilever while it is in a groove, and that makes me doubt the efficacy of ultra high accuracy alignment solutions.

At the very least, if you are going to need to take the trouble to use a MintLP for optimum sound, you should also be prepared to go to STUPID lengths to set antiskate. As in, you might want to consider changing the antiskate for each track on a side.

HI Mark,

Naw, you're not rude in the least. I live near Boston. Trust me. I know rude. ;-) It is often hard to get meanings across through forum posts. This is especially true for me since I am pretty challenged with the written word. Dammit Jim! I'm an engineer, not a journalist.

I am not saying you are wrong to consider yourself done with alignment. I suppose I'm just forcing my version of "done" as it applies to cartridge alignment. When I was a kid and would bug mom about when dinner was ready, she would always say "it's done when I say it's done".

That is my opinion regarding cartridge alignment. It can always be improved, and Yip has given us the tool to do so. I've done this alignment process several times and I do agree that the most immediate and noticeable improvement comes with that first session. I agree that this is because of the improvement in setting the overhang. However I have gotten more improvement since with a few more sessions where I am mostly trying to improve the stylus alignment with the cross hairs.

Now, some of this can indeed be contributed to finding better lighting and visual aides. The better you can see that tiny stylus on those tiny lines, the better you can adjust and the better results you can achieve. For myself, each time I improve my ability to see what is happening on the protractor I find that there is room to improve. And what I'm experiencing goes right along with what Yip has told me about what is possible. The issue is that after the first session or two the adjustments require finer and finer motor skills in order to nudge the cartridge ever so slightly one way or the other. I will agree that going beyond this point is bordering on obsession. But it is an obsession driven by the rewards in the improvement of playback due to better alignment.

Rtollert,

You'll need a lot more mathematics than that to worry me. :-)

Seriously, I don't dispute anything you have offered. I believe we are all aware that there are many, many forces acting on our cartridges. Some we can do something about, many we can't.

I am not familiar with the OC9 and what stylus profile that cart uses. I also have no idea how you set your table up. All I can offer to you about the possibility of improving what you have now is to perhaps contact Yip and ask if will give you a trial period. He is a very nice guy and I've not heard of anyone who hasn't been completely satisfied with how he has taken care of his customers. (Contrast that with Wally Tools.) I'm not trying to sell anything. I have no connection with MintLP other than to be a very happy customer. There is quite a number of vinyl enthusiast, most of whom are miles ahead of me in experience and hearing acuity, who were just as skeptical as you and Siniy123 about what could be achieved with this protractor. I was as well. Almost to a person, those who have tried using this protractor have been very surprised and very happy with what they were able to coax out.

As to anti-skate, that is a whole 'nuther conversation. I'll make it short to say that I, and many others, stopped using test records to set AS a long time ago. I use a couple of o-rings that weigh just a few tenths of a gram to adjust AS on my Triplanar. The total AS weight I use is just under a gram. If I could get away with no AS, and I can on about 80% of my 2000+ LPs, I would never use it. Nothing squashes dynamics more than AS. I do something very similar with VTF.

Rtollert/All,
This where of course where you sort of leave me in the dust, math is not my forte. I do understand, note, and agree with the fact that many different forces are all taking place simultaneously on the Stylus-Groove Interface, and all do impart thier sonic qualities.

You are no doubt correct that incorrect anti-skate will impart incorrect geometrical alignments of the Cantilever, and in turn skew the Stylus in the Groove Wall, something that is no doubt highly critical, especially with a radical line contact-micro line Stylus.

But isn't this something that should be dealt with, with anti-skate settings, rather than us end users perhaps trying to compensate by intentionally skewing our zenith angle to achieve optimum settings-results?

About the only contributions I can offer and note in my personal experiences, is that this was one important area which I feel the Mintlp Tractor very easily surpassed the abilities of the TB Tractor.

Before I set out to use my newly recieved Mintlp Tractor, I sat down for a number of minutes, Table in front of me, and checked my previous setting with the TB Tractor. All looked well in regards to alighment, both as far as overhang, and zenith angle were concerned. I used the exact same methods of using Yip's lighted magnifier, and his "Lupe" as he calls it. (Loupe)

From what I could determine from the TB Tractor, I had a perfect alignment. The Cantilever (at rest at least) was perfectly aligned, with Stylus precisely touching down within both Null Grid's little reference square.

Then I swapped out, and began with the Mintlp. Firstly, I immediately noted that my Stylus was not properly tracing the Mintlp Arc, being slightly short at arc beginning at edge of platter, and slightly long at inside travel of Arc. I estimate my errors at both ends of the Arc were +-1.5mm to 2mm.

I at first ignored these errors to then go to both Null Grids, and see what degree of errors there were with the Mintlp. The errors were slight, perhaps less than +-1mm, but they were unquestionably there. The Cantilever was as well skewed slightly crooked at Both Null Grid Lines.

The reasons I conclude for these differences, was one, that the resolution detail of the Mintlp being much finer, finally allowed me to correctly see for the first time these not before seen errors, two, the design principals of the sight line LP Tractor is a shortcoming, thus allowing a somewhat vague interpretation of accurately sighting the exact precise center of the Tonearm Pivot, even using Doug Deacon's smart suggestion of enhancing the accuracy of this tractor with a piece of fine thread to aid in pointing the Tractor.

And perhaps lastly, and this is a possibility, and one that entered my mind, how great of a degree is/was the quality control of the TB Tractor, to insure correct, exacting placement of the Sight line, the positioning of the two Null Grids, and last but not least, where the Hole was drilled for the Spindle, as any slight error for the hole placement would completely skew the hoped for accuracy?

Of course, the same concerns would hold true with any similar Protractor, that extreme measures were taken to insure a perfectly accurate geometric tool.

With all that being said, (whew!) Wouldn't then an inaccuracy with achieving both highly accurate Overhang, and Zenith Angle only compound-worsen the errors you previosuly mention? I would assume so.
Mark