MM(MI)唱头其实有多种, 当中有Induced Magnet(ADC), Variable Magnetic Shunt (Ortofon), Moving Flux(Glanz), Variable Reluctance(AKG) , Flux Bridger(Grado)和Moving Micro Cross (B&O)等的不同设计. Ortofon 的Variable Magnetic Shunt系列 (VMS 20/30/10) 设计是Induced Magnet的改良, 如我没有弄错的话 M20FL Super 应该算是MI头.