BaerWald vs VPI setup protractors

I wasn’t very impressed with the VPI protractor - too many potential error points. My current table came with a similar protractor. It has the same problem, most notably the poor choice of grid lines and somewhat loose fit of the jig. Most of the available Dennison style protractors don’t fare much better. They typically don’t match the thickness of an LP, the pivot locating rods leave room for error, and the spindle holes are too large.

If you want utmost accuracy, believe it or not, the best protractors are free. They are printable arc protractors that avoid all of these problems. The best of these is available from Conrad Hoffman’s software. You can download it here:

http://conradhoffman.com/chsw.htm

Click on "custom arc template generator..."

You only need to know the distance between the tonearm pivot and platter spindle. This is often published in tonearm specs or you might find it on the Vinyl Engine site.

You’ll want to use the "Lofgren A" (Baerwald) and "DIN" choices.

If you carefully cut the spindle hole (I use a razor blade), it will fit very snug. You adjust your stylus overhang so that it follows the whole arc, then adjust the zenith so it aligns with at least one of the grids, though I can usually get mine to align to both. You repeat this cycle until everything is perfect.The real beauty of this protractor is the grid lines for the cantilever. It has thin lines that will be perfectly parallel to either side of the cantilever when you get it right. This really helps to avoid problems with parallax error that are common with most protractor designs. It also allows for alignment at the exact height of the playing surface (you just tape the protractor to the top of an old LP).

I’ve used dozens of protractor variations, some that were quite expensive, and none yielded results as good as this free arc protractor.

@cleeds

The Conrad arc protractor does well without a mirror because of the thoughtful design of the grid layout. If one views the cantilever straight on (not quite from above, but as though one is looking down a barrel), it's quite obvious if it's off by even a small fraction of a degree. I encourage you to try it for yourself.

I would agree with you when it comes to most other protractors, where the grid lines are much too far from the cantilever, or they only include one reference line down the middle of the grid.

The problem with the Mint protractors and the like is that they don’t measure at the exact height of the playback surface. One might be able to experiment with mats and such to approximate a similar height, but it still won’t be as accurate as placing thin paper on an LP. As I mentioned in my first post, another problem with most tractors is spindle hole size. All the Dennison style tractors I’ve used have too much slop at the spindle hole to allow for reliable results.

@lewm 

I posted a link to the arc protractor software in my first post. It prints exactly 1:1 on most printers I've used. 

I would never trust a printed on paper protractor on a high-end turntable. I’m an architect, and deal with skilled accurate drawings every day. Even with good quality printers on good heavy gauge bond paper things can be ever so slightly off. First paper shrinks and expands based on humility. Second printers don’t necessarily print perfectly, depends on how they print and to how acutely the paper mechanism rolls the paper as print, thirdly and most importantly the hole needs to be man made and when fractions of a mm count that’s too much risk. Don’t get me wrong if all you want is a generally OK alignment then maybe paper is OK but I would never trust that on the high-end turntable. Factions of a mm matter

Well, I can’t speak for the effects of "humility" or "factions of a mm," but having used a number of the Dennesen/ Feickert style protractors, I concluded they are far more prone to significant error. This is especially true because they rarely mimic the height of the playback surface. Their spindle holes are typically fixed and often have close to a whole mm of slop. You won’t find that problem with the common printable protractors. Then it’s up to the user to eyeball whether the guide rod is centered over the tonearm pivot - another potential point for egregious error. When you add these all up, you might be off by whole millimeters rather than just fractions.

@2channel8,

The Conrad Hoffman protractor includes two reference lines for measuring print accuracy, both vertical and horizontal. After printing one on standard office paper, using my cheapo Brother printer, I measured the lines with my Mitutoyo vernier calipers - they were absolutely perfect.

I happen to own the DB systems protractor. It can indeed be used to align the cantilever, but ultimately, I find it's no more useful than a basic 2-point protractor.