然而依据IEC 60268-3:2018 Sound system equipment - Part 3: Amplifiers对于平衡式传输的定义Only the common-mode impedance balance of the driver, line, and receiver play a role in noise or interference rejection.This noise or interference rejection property is independent of the presence of a desired differential signal.只有驱动器、线路和接收器的共模阻抗平衡才能在噪声或干扰抑制中发挥作用。这种抑制噪声或干扰的特性与是否存在期望的差分信号无关。IEC 60268-3:2018标准 Sound system equipment - Part 3: Amplifiers音响系统设备 - 第 3 部分：扩大机
而且AES14 也允许3P卡农 作为非平衡连接但是NOTE If an unbalanced amplifier input is to accept a balanced microphone, contact 3 (or 3 and 5) of the input shall be connected to contact 1.注意 如果非平衡放大器输入要接受平衡麦克风，则输入的接点 3（或 3 和 5）应连接到接点 1。
5.4 Ground referenced transmittersGround referenced transmitting device outputs shall meet the following conditions in table 1 during normal operation under open circuit condition.A DMX512 device may have any number of Ground Referenced transmitter ports. Ground Referenced transmitter ports may be used by all DMX512 devices including ones that provide any number of non-DMX512 input or output ports. Adherence to this topology allows a DMX512 transmitter connector to be marked as shown in table 9.Because the transmitter in this topology is grounded, the existence of an isolation barrier between the transmitter and any other part of the device shall NOT qualify output for marking as ISOLATED.5.4 接地参考发射端在开路条件下正常工作期间，以地为参考的发射设备输出应满足表 1 中的以下条件。DMX512 设备可以具有任意数量的接地参考发射器端口。接地参考发射器端口可由所有 DMX512 设备使用，包括提供任意数量的非 DMX512 输入或输出端口的设备。遵循此拓扑允许对 DMX512 发射器连接器进行标记，如表 9 所示。由于此拓扑中的发射器接地，因此发射器与设备任何其他部分之间存在隔离栅将不符合标记为「隔离」的输出。
5.6 Earth grounding of data link common for receiversThis Standard defines several allowable topologies for earth grounding of data link common and circuit common for receiving devices. These are to be known as “non-isolated” and “isolated”. The preferred method is “isolated.”A specific concession is available to manufacturers of non-isolated receivers who, for reasons beyond the scope of this Standard, require a direct link between data link common and chassis.Non-isolated and grounded receivers are addressed in Annex A.5.6 接收器共用的数据链路接地本标准定义了接收设备的数据链路公共端和电路公共端接地的几种允许的拓扑结构。这些被称为“非隔离”和“隔离”。首选方法是“隔离”。由于超出本标准范围的原因，需要在数据链路公共端和机箱之间建立直接连结的非隔离接收器制造商可以获得特定的优惠。非隔离和接地接收器在附录 A 中讨论。
4.4 Connectors built into microphone casesThe designated shield contact and the shell of the microphone connector shall have a direct-currentconnection to the shielding of the microphone via the lowest impedance path possible.See Figure 4.When EMI rejection circuitry is present it shall return EMI currents to the interface shield connection point with the lowest practical impedance.NOTE: Connections that utilize the retention screw of XL connector shells are typically unreliable electrically and mechanically. It has also been shown that the inductive reactance of such a connection will result in common impedance coupling (the "pin 1 problem") at very high radio frequencies. See Brown and Josephson 2003, and Annex A.图片引用自 AES48 著作权利归属于AES所有
4.4麦克风外壳内建连接器指定的屏蔽触点和麦克风连接器的外壳应通过尽可能低的阻抗路径与麦克风的屏蔽有直流连接。参见图4。当存在电磁干扰抑制电路时，它应将电磁干扰电流返回到具有最低实际阻抗的接口屏蔽连接点。注意:使用XL连接器外壳的固定螺钉的连接通常在电气和机械上不可靠。还表明，在非常高的无线电频率下，这种连接的感应电抗将导致公共阻抗耦合(“引脚1问题”)。见Brown and Josephson 2003和附录A。
