Best Alignment Protractor?

Sorry, but there is no single "perfect theoretical alignment." There are several well known alignment schemes. They even have names, and some are promoted by tone arm manufacturers.

None of them is perfect, as the alignment of all of them is wrong almost all of the time.  The issue come down to where you want your mostly misalignments to be.

@melm

You’re not wrong but "perfect theoretical alignment" to the scheme used by Mint. That is, overhang and zenith, compromise that it is. Once you’ve used a Mint you know the reference.

"'perfect theoretical alignment' to the scheme used by Mint" is, I'm afraid, an oxymoron.  There is so much misunderstanding about setting up cartridges that is only enhanced by such statements.

Mint probably uses one of the usual standards, Baerwald, Lofgren, Stevenson or whatever, but fails to note in its advertising what that standard is.  Reason enough IMO to stay away.  The popular ones have been known for at least three generations.  My guess is that they use the most popular one, Lofgren B.  It is used by most devices whether expensive or inexpensive.

@melm  

I used 

“Perfect theoretical alignment”  as meaning perfect overhang and zenith for the scheme used, knowing full well that the scheme is a compromise and not tracking perfectly at all places on the record.  No need to read more into it than that.  If you used a Mint you would realize the point.  The amount of extra work and time and frustration of the Mint yields no advantage.

@dogberry I’d considered buying one of several “pricey” alignment jigs(protractors, gadgets) while using an SME 3009 S2 tonearm with several cartridges.., I was using basic Hudson HiFi (my dog’s name is Hudson - seemed like a no-brainer) tools and then bought a paper Tracking Wizard protractor from a guy in Poland (IIRC. Ebay anyway) which worked well. I use my eyes, ears and Ortofon test record and was pretty happy with the setup but wanted better. I finally went ahead and bought an SME V about a month ago in original box with tools and hardware and, using the alignment tools provided and instructions seemed anticlimactic at best, total time involved after mounting cartridge and arm - about a half hour. It’s now with SME tonearms in Canada awaiting rebuild, rewiring (1.2m continuous Cardas wire from cartridge clips to RCA jacks recovering several dB signal insertion loss along the way) and with any luck I’ll have it back by Christmas. New Year’s then… So I saved a couple hundred bucks in alignment tools by buying a tonearm that cost ten times as much as the tools. A once in my lifetime investment. YMMV. BTW 3009 tonearm is listed on ePay now.