Engineering consideration of ceramic phonograph pickups

Performance of ceramic pickups is compared to Rochelle salt and magnetic pickups. Whereas voltage-temperature characteristics of barium titanate ceramics and Rochelle salt crystals are relatively constant over a range of temperatures, ceramics exhibit a more stable capacity vs temperature characteristic than does Rochelle salt, and are not subject to damage due to arid and tropical conditions. The performance of piezoelectric pickups and magnetic pickups is analyzed with respect to the standard recording characteristic. It is concluded that crystal pickups are outstanding when high output is the principal requirement, where quality requirements are moderate, and climatic conditions are benign. Ceramic pickups are the logical choice when quality and economy are both important or where climatic conditions are severe or when magnetic induction is a problem. Current magnetic or dynamic pickups are indicated when the available amplifying equipment, or the present-day public opinion are the principal factors.