For dynamic pre- emphasis and de-emphasis, their frequency characters are opposite Exchange circuits were applied in the references [1～3], ie, in order to get de emphasis,the main emphasis networic and unlinear emphasis network were exchanged.
动态予加重及去加重，频率特性是相反的、文献［１～３］都采用相应的互换电路，即实施去加重是把予加重屯路的主加重网络与非线性加重网络互换。