Headphone amplifiers with XLR output
XLR
— the XLR connector has several varieties, differing in the number of contacts; however, all of them have contacts in the form of characteristic pins ("pins") and a round rim, complemented by a separate latch for maximum connection reliability. And as an additional audio output in headphone amplifiers, a three-pin XLR version with balanced connection support is most often used.Such an interface outputs a line-level analogue signal on a "one channel per connector" basis; so an XLR output usually includes at least two hardware jacks, stereo left and right. As for the balanced connection, this is a special format that uses three wires per channel (instead of the standard two) and a special way to process the signal at the receiver input. Due to this, interference arising from third-party interference in the connection cable is mutually canceled when it arrives at the receiver; in fact, the cable itself plays the role of a noise filter. This allows you to work even with fairly long wires without compromising the purity of the sound. On the other hand, the XLR connectors themselves are quite large, and the support for a balanced format affects the cost of the device. Therefore, in general, this interface is considered professional, it is installed in amplifiers of the appropriate level, and only stationary ones — it makes no sense to use additional outputs of this type in portable models for a number of reasons.