自Ｈｉ Ｆｉ有史以来 ,最常用的模拟信号传输方式有不平衡同轴 (ＲＣＡ)和平衡同轴 (ＸＬＲ)两种方式 ,它们都是“低输出 /高接收”的电压信号传输方式。这种方式要求上一级器材的输出阻抗要尽量小 ,而下一级器材的输入阻抗要尽可能提高。九十年代中后期以后 ,美国顶尖级音响名 Since Hi Fi, the most commonly used analog signal transmission methods are unbalanced coaxial (RCA) and balanced coaxial (XLR), both of which are “low output / high reception” voltage signal transmission. This approach requires that the output impedance of the upper equipment should be as small as possible while the input impedance of the lower equipment should be as high as possible. After the mid-and-late 1990s, the United States top audio name