BaerWald vs VPI setup protractors

This issue of horizontal tracking angle (HTA) is an interesting one.  There is no single correct setting for a pivoted offset arm.  This is unlike azimuth where there is an unambiguously correct setting and we all try to get as close as possible.  It is also unlike SRA where (at least for each record thickness, or possibly record) there is only one correct setting.

When we deal with HTA we understand that it will be wrong most of the time except at two (or even one) radii.  So we make a choice of where we want the various levels of distortion to appear. Each of the proper names associated with HTA (including HW) prefers their distortion in another part of the record.

I am always amused when I read posts claiming that after getting the newsuperdupercustommade protractor the sound of the system blew away anything heard before.  It is sometimes alleged to have made a cheap TT sound like an expensive one.  Since we are almost always tolerating HTA tracing distortion, using instruments with medical precision is not really necessary.  But as for me, as long as I'm bothering, I try to get it as close to Lofgren A as I can.  At least it makes system evaluaton more consistent.

As I wrote earlier, I find all the fuss about HTA to be overblown.  A well received arm, the Viv Lab Rigid, is a pivoted arm without an offset and its HTA tracing distortion is probably the highest on record.  But respected reviewers write that given other positive attributes the distortion which so tortures us, and this discussion, is virtually unheard.  Go figure!

As a lover of analog, I'm more concerned with azimuth and SRA using my ears as the best instrument.  

@gillatgh,

I finally sent my Classic 3 Sig SE back this week to have the STP corrected. Using my Feickert protractor, the STP was off by 2mm. Haven’t listened to it in over 1 & 1/2 years. Sad.
As I suspected, apparently this issue varies for their different tables but is a wide ranging problem. BTW, in the last mm’s and closer...this is where all of the magic happens.

Good luck.

Can this small amount of variance have a sonic impact?

Yes, but don't worry. Most alignments are done wrong and the owners won't notice.

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.

The Conrad Hoffman protractor is a PDF so while printing it, have a ruler ready to measure the actual print. Increase or decrease the print scale by as little as 1 to 2% and re-print it. It's best to print it at a professional print shop with plotter type printer usually used for printing engineering and architectural drawings because they're better calibrated than multi function printer-scanner-copier machines. Sometimes a printer's calibration will be perfectly okay in horizontal direction but a bit off in vertical direction (and vice versa). In such cases go to a different print shop. Yeah, I know it's a lot of trial and running around but that's the fun of creating your own protractor:)

And regarding mirrored surface for aligning the cantilever, use any small mirror. It works perfectly as long as there's sufficient lighting in the room.