My new alignment template generator

[Conrad Hoffman]

Ok, I admit it. I tested this on the unsuspecting folks at the asylum first. After a few revisions, here's my cartridge arc alignment template and strobe disk generator. It's far smaller than bitmaps of the same thing, plus you can choose your specific pivot-to-spindle distance, groove radius and alignment strategy choice. It also prints pretty darn nice strobe disks. Freeware, no viri, no strings attached. Please let me know what you think.

http://www.conradhoffman.com/chsw.htm

[JaS]

Hi,
I haven't had a chance to check a printout yet but from a quick 'print to PDF' it looks very good!

It's shockingly simple to use, even with the ability to choose different alignment methods, inner and outer groove diameters and X/Y print error correction.

Nice work. All you need to do know is find a way for it to align the cartridge without the user getting out of his chair

Regards,
JaS

[scho2684]

Very, very nice!
As stated above, very simple to use, good work!

Regards,
Marco

[Conrad Hoffman]

Minor news flash- I just uploaded version 1.04 that accommodates longer tonearms without going off the paper. Nobody asked for it yet, but I figure somebody with a 12" tonearm will be along sooner or later!

[Conrad Hoffman]

Last changes for a while- added the 45rpm ring to the 50hz strobe disk, fixed some dumb text errors and added some notes. Give this thing a try!

[Klaus R.]

...plus you can choose .... alignment strategy

I had a look and saw that there's Baerwald, Loefgren B and Stevenson A to choose from. Loefgren was the first in 1938 to develop a solution for this problem, followed by Baerwald 1941, Bauer 1945, Seagrave 1956, Stevenson 1966. Graeme Dennes analysed the various solutions in 1983 and found that they are mathematicall identical to those of Loefgren.:

http://www.vinylengine.com/phpBB2/viewtopic.php?t=4854

see in particular e-pages 7, 8.

Give credit where credit is due! Baerwald's solution is identical to Loefgren's A-solution. Clearly, in view of these (historical and mathematical) facts, credit should be given to Loefgren, and to Loefgren alone, not Baerwald, and it should read "Loefgren A" / "Loefgren B" instead of "Baerwald" / "Loefgren B".

On a sideline, the only manufacturers that make that (incorrect) distinction (Baerwald, Loefgren) on their websites are Wally Malewicz and Judy Spotheim (La Luce turntable). I have contacted both asking to set the record straight in view of the facts. As you can see, neither has modified the site accordingly:

http://www.simplyblack.net/WVC/index_wally.html (Wally Tractor)
http://www.spj-laluce.com/products.htm (Lyla tone arm)


Klaus

[andyr]

I had a look and saw that there's Baerwald, Loefgren B and Stevenson A to choose from. Loefgren was the first in 1938 to develop a solution for this problem, followed by Baerwald 1941, Bauer 1945, Seagrave 1956, Stevenson 1966. Graeme Dennes analysed the various solutions in 1983 and found that they are mathematically identical to those of Loefgren.

Klaus

Hi Klaus,

So where does that leave us wrt the Stephenson alignment?

As I understand it, he simply chose different inner and outer null points? This has some relationship to the radius of the inner & outer grooves but, if I decide that most of my LPs have different inner & outer groove radii, what is the logic to choose the best alignment?

Regards,

Andy

[missan]

From what I can see, the Stevenson null points is according to design 1C.
Not beeing an expert on this, I have normally presumed that the design 1B was what Stevenson recommended, and what is normally also referred to as Stevenson. The 1C is a little more suited for 7" records.
missan

[Klaus R.]

Andy,

according to Graeme, Stevenson A uses the same equations as Löfgren with a different goal, i.e. zero distortion at the inner groove. So yes, basically it's only about different null points.

The problem with Stevenson A is that, while the outer radius is about the same all the time, the inner radii are really different, so which one do you choose? Whatever the approach or radius is you are using, it's a compromise anyway. You get optimum results for records having that radius and less than optimum results for all the others. I measured the inner radii of my collection and as it happens, the inner null point is approx. at the average inner recorded radius.

Has anybody compared Löfgren A and Stevenson A to see whether it makes an audible difference?


Klaus

[JaS]

Has anybody compared Löfgren A and Stevenson A to see whether it makes an audible difference?

Hi Klaus,
I tried Stevenson, Löfgren B, and Baerwald (!) and to be honest I found it very difficult to hear repeatable differences between them. I'm always surprised when people say they hear night and day differences or that a particular protractor makes a massive difference compared to any other using the same null points.

I use Löfgren A null points as technically they should be better than Stevenson and they suit the slots in my arms better than Löfgren B, but I'm not obsessive about it

Regards,
JaS

[Seb]

I'm always surprised when people say they hear night and day differences or that a particular protractor makes a massive difference compared to any other using the same null points.

me too

best regards

Seb

[Conrad Hoffman]

Glad to see some interest! I don't have any problem changing Baerwald to Löfgren A, but called it Baerwald because that's the most popular name and I didn't want to clutter up the screen with a dual name. I used the wonderful Graeme Dennes paper to sort out the formulas and, as he says, if Löfgren wrote the only paper on alignment, we'd still be doing things exactly the same way.

I learned something interesting while experimenting yesterday. When the stylus is off the record or template, the cantilever forms an angle to the arm. You knew that. When the stylus is on the record or template, the angle is reduced. You knew that too. What I hadn't thought about was that this increases the effective length of the arm slightly. Not much, not enough to really measure, but enough to put axial force on the cantilever. Because the arm pivot isn't in line with the cantilever, the cantilever will be deflected in the cartridge body towards the spindle. IMO, this makes aligning to the cantilever more problematic, especially with high compliance cartridges. Once friction is overcome, say playing a record, or if the template had zero friction, the cantilever re-centers.

What do people have to say about this- I'm far from being any expert on the topic?

[Conrad Hoffman]

Your wish is my command- Baerwald has been purged and replaced with Löfgren A, though I did keep a note in the help screen for those who are looking for Baerwald. Also defaulted the selection to Löfgren B, as that seems to be the most logical choice for most people, though as I understand things, some arms will only allow Stevenson, which accounts for most of the interest in that. Any comments on the axial force issue? I added some notes on that as well.

[Conrad Hoffman]

I'm in favor of naming things after the originator, and here it's no big deal. OTOH, the Whetstone Bridge was actually invented by Christie, but if I talked about a Christie Bridge, everybody would think I'd flipped!