Dear
@moonglum : Thank’s, you are rigth and yes: who’s counting but me. Good.
Ignorance is the " war’s mother " and that’s why I always try to improve my ignorant levels.
@moonglum in confirmation to your posts and mine here high-ligths from specific experts studies on the subject and its importance:
"""
The stylus tip, when in good condition, touches the groove walls at only two points. The entire weight of the stylus and the structure which holds it is concentrated at these two microscopically small points. When this concentration of pressure upon the points of contact is calculated, we find it to be approximately 26 tons per square inch. The walls of the record grooves are, of course, subject to the same pressure, but only for the fraction of a second required for a particular section to move past the tip as the record rotates. The stylus tip must travel well over one-half mile of surface each time a 12" LP record is played...with 26 tons of pressure per square inch. """
""" The most interesting photos to me described the "infinite" amount of force applied to the groove by the spherical and elliptical stylus designs. These designs effectively rest on 2 round contact points about 80%-90% of the way down into the groove. Since the contact points are rounded, the contact area is infinitely small, so no matter what the tracking force, the tracking pressure at the point of contact is effectively infinite. """
""" Getting back to the ripples caused by spherical and elliptical styli near the bottom of grooves, there seem to be 2 forces at work. The stylus tip gets warm on the two contact surfaces after only a few seconds playing. At that point you have a hot stylus pressing infinitely hard against vinyl and this can easily create substantial softening (melting is not required, in fact melting is not the mechanism that creates the ripples). After the stylus has passed any groove location the after-effect of the stylus bouncing merrily along in the groove causes the rippling. ..... But there are so many stretching, bouncing, musical, pushing/pulling pressure waves being generated, some driven into the disc and some being generated as the stylus tries to drag the vinyl along with it, that as the soft vinyl hardens again, it reacts in a resonant fashion. ""!"
""" From page 975 : "because of the small area of contact that exists between the stylus tip and the groove, the pressure against the groove wall can rise up to many thousands of pounds per square inch. For instance, if the wall receives 0.7 g of force applied through the contact area equal to 2 ten millionths of an inch, the pressure is 7726 lb/squ.inch. It has been experimentally shown that with such high pressures and forces of friction between stylus and the vinyl, that the outer skin layer of the record material melts as the tip slides over the plastic and then refreezes almost as fast as it melted. It has been suggested that since the melting temperature of vinyl is about 480 °F that the same temperature exists in the contact area. If the record material is metal, which happens when metal mothers are played, then the pressure increases to 20,000 to 30,000 lb/squ.inch, and the temperature can reach 2000°F because there is no plastic deformation of the groove wall. This explains why styli made of diamond, which is nothing more than carbon, literally burn up or wear out in a couple of hours when they are used to play metal mothers. """
In my past post I don’t speak of other parameters that can increment/modulate those very high forces that per sé increment the unstability problem in the unipivots during playback.
The recorded grooves were recorded at different recording velocities according the music information needs this has a direct effect on those forces that push the tonearm bearing, stylus tip shape has its own effect as the stylus tip wear through the time that between other things increment the friction between stylus tip and recorded grooves in encrement on those forces, skating has an effect too as the VTF and SRA that it’s changing almost at each groove due to LP imperfections. Of course that self cartridge tracking abilities contributes too.
All those very high forces affects any kind of tonearm bearing designs but on unipivots is the worst case.
@stringreen , I posted:
""" As always I’m not talking here if we like what we are hearing through unipivots or dislike, this is not the issue but to stay nearer to the recording that means we need to stay with distortions ( of every kind. ) at minimum and unipivots can’t help to achieve that main target. """
That’s what I’m talking about. As unipivots does not exist any single tonearm design with out trade-offs and each one of us choose which trade-offs are better choosed to be nearest to each one targets. Unipivots are out of question to achieve my today targets.
It’s nothing wrong with you because your system today fulfill your targets. Fine, that's what each one are looking for.
Btw, thank’s for your invitattion and you are welcome to come at my place in México city anytime.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
Btw, as always the post of that person came only to " hit me " ( obviously with no success. ) with no single fact because has no facts. Pity.
