SOTA NOVA, HR-X VPI, Technics 1200G recommendations?

If you read the article Hugh Finnimore, Disc cutting in theory, Studio Sound and Broadcast Engineering, July 1975 Studio-Sound-1975-07.pdf (worldradiohistory.com) and can tackle the math you will get a much better 'technical' understanding of what is actually happening with the stylus.  When talking about the record velocity - the important item is groove velocity - 'tangential velocity' (also called the linear velocity) - and for a 33 rpm 12" record this is decreasing from about 51 cm/sec at the outer groove to about 20 cm/sec at the inner groove.

This is going to come as a shock, but stylus acceleration can exceed 1000-g's.  This is not a typo, and in-fact, when cutting the record, they generally adjust parameters to generally limit the stylus acceleration to 2000-g's.  The acceleration is a function of the stylus velocity which is driven by the frequency to reproduce, and the signal amplitude (displacement) which is often called modulation.  But, the inner groove is the most difficult for reproducing the higher frequencies and largest modulations which is a challenge for classical music with its end of program crescendos.

The stylus radius - its profile - has a profound effect on the ability to trace the highest frequencies and largest amplitude/modulation; and this where the advanced profiles such as Shibata come in.  Read the above article for real technical details.  The magazine also has a survey of some of  the cutting machines that were available.  When you realize the enormous accelerations that are occurring it may make sense why some cutters such as the NEUMANN are rated at 500W/channel and the cutting head has to be helium cooled to achieve highest groove-velocity.

In this old Stereophile magazine - the next to last page, there is a good composite plot of the velocities and the displacements vs frequency with limits of the stylus radius for a 33 rpm record -  Stereophile-1964-08.pdf (worldradiohistory.com).  You will see similar composite plots in the  Studio Sound and Broadcast Engineering, July 1975.

@antinn , Thanx for a very lucid explanation. 1000G's, that means the groove is subject to a force 1000 times the weight of the stylus over the styluses contact area. A formula 1 driver is subject to something like 5 G's under braking. 1000 G's that is nuts.

@mijostyn, and anyone else,

The article Dr. A. M. Max, Disc Phonograph Records, Max, RCA Engineer Magazine 1966-08-09 1966-08-09.pdf (worldradiohistory.com) derives the same formulas addressed in the Studio Sound and Broadcast Engineering, July 1975 but takes it further showing the derivation and calculation of the forces/pressures the stylus exerts on the record taking into account basic record material properties; with spherical stylus at 2.5 gm VTF able to develop over 65,000 psi. The ’forces’ involved in record playback are just amazing. The fact the record playback is still valid today is a real tribute to the scientists & engineers and the associated corporate R&D centers that did the heavy lifting 50 yrs ago.

PS/In may last post, I should have said  "...NEUMANN are rated at 500W/channel and the cutting head has to be helium cooled to achieve highest groove-stylus-velocity."  There is always 2 different velocities - the record velocity as it moved under the stylus and then the stylus velocity as it traces the groove amplitude/displacement/modulation up/down and side-to-side.

I like the term linear velocity vs groove velocity. Yup if you look at a Neumann lathe it is obvious that there is some serious stuff going on with the head. That they can keep the whole mess quiet is more amazement.
Thanx for the article antinn.

@antinn, Dr Max looks just like Harpo! Fun to read older rags like this. Those were the Dynagroove days:-)