@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.
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.