Your amplifier power cord is equipped with a standard three-prong grounding plug which, if used normally, will ground the chassis to the power line. (您的放大器电源线配有标准三脚接地插头,如果正常使用,机壳接地。) While this procedure provides the maximum possible safety in use, it will, in many cases, cause your audio system to have a residual hum. (这一过程提供了最大可能的安全使用,它会在许多情况下,导致您的音响系统有残余的嗡嗡声。)
It is usually best to keep the preamplifier "earth grounded" and "float" the grounds of power amplifier and other equipment to eliminate ground loop hum. (通常最好保持前置放大器“接大地”功率放大器和其他的设备“浮地”,以消除接地回路的嗡嗡声。)