[regentone001]

So BSR and Ronette both sold cartridges and styli knowing that they would do damage to the new and very expensive stereo records that were just coming out? Somehow I don't think that would have done their reputations any good at all and they would know it.

The stylus in a stereo groove does not move vertically up and down. The walls of the groove are at 45degrees and the stylus moves 45 degrees to perpendicular