Stylus Force Guages - why extreme accuracy?

We've talked about this a number of times, and it appears that many seasoned audiophiles enjoy having highly accurate gauge in order to re-set the cartridge to a previously determined optimal tracking force. Reasons for this range from swapping cartridges and/or armtubes periodically to making VTA changes in arms that can have their tracking force thrown out inadvertantly in the handling process.

Then, there are folks like me (and possibly you) who don't have these needs and rely on fine tuning by ear with a gauge like the Shure just to get us in the ball park to start that process. I follow Lloyd Walker's turntable fine tuning advice for iterative adjustments of VTA and VTF to do my fine tuning. Then I adjust VTA for each different record weight, leaving VTF fixed. (The small VTA adjustments between 150, 180 and 200 gram LPs are very noticeable and absolutely necessary for my ear and my system, but they don't interact enough with VTF to warrant changing the VTF for each of these subsequent VTA teakings.)

Sdcambell, my experience has been that for setting up a tonearm/cartridge an iterative dialing process of changing VTF, then changing VTA, then changing VTF, is needed because of the interaction (just as Lloyd recommends). Thereafter, as noted above, I don't bother changing VTF when I adjust VTA between LPs because the difference truly is miniscule to unnoticeable at that point.
.

Anyone remember their college physics? How much of an error will be caused by having the stylus 1/2 inch higher or lower than the record surface? I doubt it is much, but haven't cracked my textbooks to do the calculation. Anybody?

Peter_s,

Having one's stylus 1/2 inch higher or lower than the record surface would have a HUGE impact on sonics, namely, there wouldn't be any! ;-)

To respond seriously, we've discussed various explanations for the audibility of SRA/VTA adjustment several times over the years. An archive search will turn up several endless (and occasionally acrimonious) threads. There's no point going through all that again.

To summarize, no explanation has yet been posited that explains what people hear while satisfying the mathematically skeptical. Conclusion: the state of scientific knowledge still trails our experience of reality in this area.

If you're serious about researching this question, I'd recommend beginning with some archive searches here and at VA. You'll find enough material to keep you reading for weeks. I particularly recommend one article in the VA FAQ's, Jon Risch's "VTA once and for all". It comes closest to explaining what I hear, yet skeptics have expressed doubt that the degree of changes involved could be audible. They would prefer an alternate theory, but no more satisfactory one has been found AFAIK.

One long and inconclusive thread here was blissfully terminated by a practical post from Tbg. He wrote, "If you hear it adjust. If you don't, don't." Not a productive attitude for the scientific investigator, but a very productive one for the music lover/audiophile.

Nice reply, Doug. I think you captured it well.
Regards,

Peter_s,

Why not try it yourself and come back and let us know what you find out? Get a scale with some degree of accuracy and precision, say .01 gram +/- .005. Then take a reading at record level and one at 1/2" above (and below if you can). Keep in mind that by adjusting vtf you are changing the static location of the windings to the magnets. Biasing the circuit in a way. So it does not work against physics to suggest that minute changes in vtf can make a difference in the sound. This is probably not going to make any difference with some cartridges but it most definitely does with others. Now through in the mechanical action of the arm and bearings involved and you can see how there may be more or less resistance to slight changes in vtf from the stylus all the way back to the counterweight on the arm. It is all physics.

I don't think it is necessary to have a vtf guage that can measure to .01 in order to enjoy good playback, but it can be very useful with some equipment. And you don't need to spend $800 on the Winds. That $95 guage being sold here by ANS works very well.

I've had the pleasure of hearing Doug's rig. It sounds wonderful with any record. I have also heard the difference on some records when he makes minute changes to VTA. There is a very noticeable improvement. Not all pressings show this but the ones that do show it it very will. Granted this doesn't speak to vtf changes but I have no doubt that the table/arm/cart combo he is using is capable of showing what differences these slight changes can make.

"If you hear it adjust. If you don't, don't." That pretty much says it all.