大家知道,磁带的磁滞回线都是非线性的,录音时必须设法加以解决,否则将会产生很大失真。为使输入信号工作点移至磁带磁滞回线的线性段,必须给录音磁头加入偏置电流,这种偏置方法叫做偏磁。偏磁方法有直流偏磁和交流偏滋两种。如果送入录音磁头的偏置电流是直流电流时,就是直流偏磁法。采用直流偏磁法录音,在磁带上会记录下直流剩磁成分,使录音机产生磁化噪声,所以,一般是不采用的。日前,录音机几乎都采用交流偏磁法,用频率比录音信号的最高频率大5倍以上 We all know that the tape hysteresis loop are non-linear, recording must be managed to be resolved, otherwise it will have a lot of distortion. To move the input signal point to the linear section of the tape hysteresis loop, you must add a bias current to the recording head, this bias method is called bias. Biasing methods are biased DC biased AC bias and two. If the bias current into the recording head is DC current, it is DC bias method. The use of DC bias method of recording on the tape will record the DC residual magnetic components, so that the recorder produces magnetization noise, therefore, is generally not used. Recently, almost all the recorder using AC bias method, with the highest frequency than the maximum recording signal frequency more than 5 times