采用平衡法传输信号，一般不会出现严重的交流声干扰。但是当信号两端使用不同电源时，这种问题就可能发生。
The balance method of signal transmission, generally does not appear the AC noise interference. But when the signal ends using different power supply, this problem may occur.
这种干扰会影响信号质量严重了还会反馈到主信号里,出现严重的交流声。反复检查济南音响音频信号接法如平衡，不平衡改变相位用四芯屏蔽以及加装隔离变压器等都不能解决。原因就是当信号两端的设备使用非同一电源所造成的。大家可以测量两端电源接地点的电位差如果很大，那么这个电位差就足以通过屏蔽线在回路中产生强大的交流干扰了。
This interference can affect the signal quality seriously will feedback to the main signal, severe hum. Repeated inspection Ji'nan stereo audio signal connection such as balance, unbalance change phase with four cores and the installation of isolation transformer can not solve. The reason is when the signal at both ends of the device using the same power caused by non. We can measure both ends of the power ground potential difference if large, then the potential difference is enough to through the shielding line in the loop to generate strong AC interference.
济南音响 http://www.jnzqyx.com/ 的解决方法就是将屏蔽线两端一端接地，使其仍然有屏蔽作用，而将另一端悬空。使两个接地点的电位差不能在连线中产生回路，交流声也就不再产生了。
Solution to Ji'nan sound is shielded wire ends is grounded, which still has the function of shielding, and the other end is hung. The difference does not produce loop in the attachment to potential two ground, hum will no longer produce.