The Case for Precision Stylus Alignment

I made out easy over the years.  My first and second new cartridges were a Grado from the mid 70s and the Grado GF3E+, purchased circa 1980 or so.  When I bought the GF3E+, the dealer used a metal Dennesen Soundtractor to align the cartridge, and even proceeded to grind the front lip off of my headshell so it could align properly on my turntable.  I liked the protractor enough that I ordered one, in plastic.  $35 at the time.

When I replaced the GF3E+ with the Shure V15 Type V-HE in 1982, the V15 came with its own alignment jig, so setup was even easier.  At some point in 1983 or 1984, I had purchased a Dynavector DV10X3, and the protractor helped me there also; even with its rounded sides, I was still able to line things up with the sides and the cantilever.  Too bad the cartridge, well, sucked.

Fast forward to the present.  The V15 had been through a handful of stylus replacements (due to wear and clumsiness, I’ll freely admit).  Since replacement styli are nowhere to be found (other than retips or third party replacements), I ended up buying an Ortofon 2M Black.  I knew the Shibata would be a finicky stylus tip to align.

With my last Shure replacement stylus from several years ago, I had noticed that the cantilever was a hair off, and with my eyes playing tricks on me, I could have sworn the diamond was also “tipped” very slightly to one side.  (It still played wonderfully, and could play through all six tracks of the Shure Obstacle Course without breaking up, something which no other cartridge has ever done before or since in my system).  That got me thinking seriously about manufacturing tolerances, especially at the microscopic level.  And it also got me thinking that conventional alignment wisdom is all thrown out the window once we start aligning to the stylus tip vs. other components in the chain.

Let me break it down.

Conventional theory says we should align the cartridge so that it lines up on a protractor properly.  Many use the sides of the cartridge; others use the cantilever itself (which is actually more accurate, in case it is canted off to one side very slightly).  Yet this focuses on the cantilever and/or cartridge body, not the stylus tip.

Now, we are also focusing on the azimuth angle.  Looking at the front of the headshell, it should be parallel to the playing surface–the turntable, or the record itself.  Or in other words, the top surface of the cartridge should be parallel to the playing surface.  Again, we are not focused on the stylus tip.

Finally, what about VTA (vertical tracking angle)?  Some tonearms can be adjusted for height at the pivot point.  There seems to be different trains of thought there also.  Align it so your tonearm is perfectly level?  Align it so the headshell is parallel to the playing surface front-to-back?  Use VTA as a tone control to adjust the treble or bass, lowering it or raising it at will?  That certainly seems the least accurate of all, and is pure guesswork on the end user’s part.  And here again we are not focusing on the stylus tip.

Why all this focus on the stylus tip?  In theory, the stylus tip should be at a right angle to the playing surface as viewed from the front, it should be at a right angle to the groove at its contact points, and something called the stylus rake angle (SRA), the angle at which the stylus sits in the groove front-to-back, should be set very slightly tilted forward, the ideal being 92°.  (There was research done decades ago that concluded 92° was the most logical accurate angle to align to.)  These alignments will most closely mimic the original cutting stylus and therefore, keep accuracy high and distortion low.

Here is where traditional alignment methods fail.  If manufacturing tolerances in the cartridge are off by a degree or two, or even more, the cartridge and arm could all be perfectly lined up.  But the stylus itself is still out of alignment. With lesser styli like elliptical or spherical, it won’t be as important.  With higher end styli, though, a degree or two can make that little bit of difference that transforms a good cartridge into a great one.

I wondered for years how this could be accomplished.  Thankfully, Michael Fremer over at Analog Planet was on a similar track and has used a digital microscope to assist with alignment.  His results have enabled him to align his cartridges much more precisely than by using less accurate methods and guesswork.

My own journey into stylus alignment was inspired by some of Fremer’s ideas, and future posts in this series will go into the alignment steps in greater detail.  Stay tuned.

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