录音机采用超音频偏磁,具有录音灵敏度高、信噪比高、录音动态范围大、失真小等优点,因而近代多数录音机都采用此法偏磁。为保证录音机的高频频响,要求偏磁频率要高于录音机工怍的最高顿率5～10倍。因此,偏磁频率范围一般选择在几十至二百千 The recorder uses super audio frequency bias magnetic, with high sensitivity recording, high signal to noise ratio, recording dynamic range, small distortion, etc., so most of the modern recorder are using this method magnetic bias. In order to ensure the high frequency response of the recorder, it is required that the bias frequency should be higher than the highest frequency of the recorder by 5 ~ 10 times. Therefore, the bias magnetic field is generally selected in the range of tens to two hundred thousand