Is extremely accurate "VTA" adjustment necessary?

restock, thank you. being involved in audio for thirty years i already had this discussion. back when my eyes were good and my hand was steady, I spent long hours into the night trying to adjust vta. back then hardly anybody cared about vta. that meant very crude methods of lowering and raising tonearm height. beleive me i scratched up more than one of my favorite records trying to adjust vta while the record was playing. you can measure arm height to very small tolerances. you will have to go outside audio to find a device to do it. the manufacturer has designed the stylus so all things being equal and the cartridge body is parrallel to the record surface you will duplicate the intended contact patch of stylus to record. trust me. that is the intent of all these cartridge adjustments. think about it. any misalignment of the cartridge either shrinks the contact patch or skews that contact patch from the center of the grove. don't worry about the angle of the cutting head. it's varying record thickness that throws of the vta of your own setup.
the other parameters are not senstive to record thickness. thus they dont vary from record to record. having said all that. the final test of anyhting audio is in the listening. if you can't hear it it aint worth the trouble. Just remember the the first magazine article i read on vta was based on mathemical proof of the signifcance of vta which was then later confirmed by the golden ears. I pitty the poor soul who is trying to find the sweet spot by ear. even if it can be done, which i doubt, it has to be maddening.

Rene,

Something new and even more awkward just occured to me. It's so obvious I'm surprised we didn't think of it before. Geoff Husband didn't touch upon it in his article either.

On nearly all tonearms, including the TriPlanar and VPI that he discussed, changing the arm height moves the arm bearing straight up or down on a line perpendicular to the plane of the record surface. There are a few rare and immensely costly exceptions (Rushton?) but this simple geometry is true for the vast majority of arms.

You see what this means. If we begin with the arm bearing on the plane of the record, ANY movement of that bearing on a vertical line, whether up or down, will shorten the stylus-to-arm mount distance.

Therefore, whenever we adjust arm height on such an arm we are altering not only SRA but overhang too. This of course means we are altering our alignment point(s). Finally, assuming a pivoting arm with offset headshell, we are altering azimuth and stylus alignment too. Oy!

Even if an arm and cartridge were set up "perfectly" in every parameter, moving the vertical pivot of the arm vertically alters that setup.

If we were adjusting strictly for record thickness then setup geometry would be preserved, but IME that is not the case. Different arm height settings for similar thickness records are common IME.

I'm beginning to believe it's impossible to reproduce music via these crazy tools at all! Fortunately, the evidence of my ears tends to overwhelm the scepticism of my brain.

Crawls into corner, sucking thumb, but still tapping toes...

dougdeacon. as long as you dont move the bdoy of the cartridge, pivot to stylus distance is a constant. you are however right in that you have alterered the overhang points. i think what you meant to say is that raising or lowering causes the stylus to fall on a different spot on the circumference of the record. it will then describe a different arc from than the one you used to optimize overhang.

Doug, that is correct, the overhang will be affected in a minor way, when adjusting VTA.

I agree it gets very difficult to make everything perfect on every record, and I don't even try to do it. I just get it as close as I can by ear, and go with it.

It is great to make things as accurate as possible, and as long as it doesn't intrude on your listening experience, then it's fine to do as much tuning as you are comfortable with.