Dumb VTA Question

It depends on the stylus type. I think that the Ortofon Replicant stylus is meant to be measured along the rear edge of the stylus while most other stylus shapes are meant to be measured along the center shank axis. MF discusses this somewhere. You may find it in his Ortofon A90 review.

Gemini05,

Expanding on Peter's response, if you're obsessive enough to visually measure SRA, what needs to be measured is the vertical contact line of the stylus. That's what actually interfaces with the modulated grooves of an LP.

As Peter implied, whether this line falls at the front or back face of the stylus or somewhere in between depends on the stylus shape.

FYI, on some styli the contact line is easy to see, on others it's difficult or impossible.

Measuring anything other than the stylus's vertical contact line would produce a number only randomly related to its playback characteristics, not a measurement in any meaningful sense.

P.S. For completeness it should be noted that conical (aka, spherical) styli have no vertical contact lines, just two contact points. The lack of any vertical dimension in their contact surfaces makes SRA mathematically meaningless for conical styli. This explains why SRA changes with such styli are inaudible, which confirms the concept stated in my first paragraph by negative example.

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So much for theory. As others have stated, visual measurement of SRA is largely a waste of time. The most it can do is put you in the ballpark prior to final adjustment by listening. There are faster, easier and less expensive ways to do that than visual SRA measurement.

You can get in the ballpark in about 30 seconds with no measuring tools, magnification or special lighting. Just eyeball to make the cartridge top surface or (second best) the tonearm visually level to the record surface. That's almost always close enough. Fine tune by listening.

In an unfamiliar system with an unfamiliar tonearm and cartridge, I can optimize SRA for a particular LP in 2-3 minutes. In my own system it's even less, since the roughing in by eye has already been done. USB microscope geeks are still hunting for their tools while I'm listening to music, with SRA optimized at least as well as theirs will ever be. ;-)

Ditto what Doug said. Life is short.

Thanks Doug.

As usual, Doug explains it as it is, or as it should be. The key is to know what to listen for. Doug explained that in another VTA thread.

I've got a USB microscope, but I use it only to take close up photos of the cartridge to confirm things I can't see quite as well with my naked eyes. eg. stylus shape, cantilever alignment, etc. It is a fun tool, but I no longer used it for SRA angles.

For a quick guide, I use a 10X loupe to confirm that the stylus is just past vertical, which is close enough to get started. Then, from there, I adjust by listening.

"I need to also give a big THANK YOU to Jonathan. He
answered several questions for me and always had the time
and guidance to give me. We really couldn't ask for better
people in the high-end business to deal with.
Mofimadness "
++++1
Pradeep