Differences between jack and XLR

In this practical tips, we explain the differences between the jack and XLR, as well as the compatibility of these electrical audio connectors.

Jack: The standard plug

In everyday life, a stereo plug or headphones and usually a jack plug are used. But jack is also widely used in professional and semi-professional environments.

With jacks with two rings (TS jack), one channel is transmitted asymmetrically (a mono signal) as an AC voltage between the signal and ground.
There are two possibilities with the supposed stereo jack (TRS): Either two channels are each unsymmetrical between channel and common ground (two mono signals / one stereo signal) or one channel is transmitted symmetrically (a mono signal).
With an unbalanced connection, the signal is simply transmitted.
A symmetrical connection uses a trick to eliminate transmission errors: The signal is transmitted normally (+) and reversed (-), i.e. with negated voltage. The sum of both signals would be zero. Therefore, the reversed signal is turned back in the terminal. Interference, for example caused by electromagnetic waves from outside, generates the same noise in both transmission channels. By turning the one channel after the transmission, the useful signal is doubled and the total of the noise is zero.
The typical jack plug is the male plug variant, the socket is female.
When inserting the male plug into the female socket, the signal and ground strip and a short crack is heard.
In a special practical tip, we explain how to repair defective jack cables.

XLR and Cannon: the competition

XLR plugs (also called cannon plugs) are mainly used in professional audio technology. In contrast to the jack, each XLR connection (if used properly) is symmetrical and therefore very quiet.

XLR has a standardized pin assignment.
An XLR cable transmits a channel symmetrically.
When plugged in, signals and ground remain separate. There is no noise.
A clamp ensures that the cable remains in the socket even under load.
XLR is fully compatible with a balanced jack.

Compatibility between jack and XLR

The jack and XLR are basically compatible. Both are typical speaker connections. However, it depends on the assignment of the cables what exactly an adapter or adapter cable transmits.

There are adapters and balanced adapter cables with which you can transfer sound from XLR to jack.
There are also combi sockets that work with both jacks and XLR plugs.
However, you can only transmit phantom power via a jack with a few devices. As described above, there is a short circuit when inserting the jack, which can damage sensitive devices.
There are also adapters from XLR to TS jack. Here two of the XLR pins are bridged for asymmetrical transmission.

Jack and XLR are fully compatible as long as the jack transmits a channel symmetrically. So more important than the question of jack or XLR is that of symmetrical or asymmetrical transmission. In the case of long cable routes or environments with a lot of interference, symmetrical connections are always preferable. Conventional phantom power is also only possible with three lines. Tips on installing a sound card and setting up a karaoke machine provide further CHIP online practical tips.