XLR vs TRS vs TS: What Each Audio Connector Does

Three connectors turn up on almost every piece of audio gear: XLR, TRS and TS. TRS and TS plugs look nearly identical, which is why people mix them up. The size of the plug is not what matters. What matters is how many conductors it carries, because that decides whether the connection is balanced or unbalanced.

The short version

The word to watch is or in the TRS row. A TRS plug can do two different jobs, and the plug does not tell you which one. You have to check what the gear expects.

TS: tip and sleeve

A TS (tip-sleeve) plug has one signal contact, the tip, and one contact for ground and shield, the sleeve. That is an unbalanced connection. It is simple and cheap, and it is exactly what a guitar cable needs: a short run carrying a signal from a passive pickup to an amp. It is also what most pedalboard patch cables use.

The downside is noise. An unbalanced cable has no way to cancel interference it picks up, so long runs can hum or buzz. For why that happens, see balanced vs unbalanced audio.

TRS: tip, ring and sleeve

Adding a ring gives the plug a third contact, and that third contact can be used in two ways.

• Balanced mono. The tip carries the signal, the ring carries an inverted copy of it, and the sleeve is the shield. Studio monitors, audio interface outputs and many mixers use this for clean connections over longer runs.
• Unbalanced stereo. The tip is the left channel, the ring is the right channel, and the sleeve is the shared ground. Headphones work this way, and so do many stereo line connections.

Plugging a stereo headphone cable into a balanced input, or the reverse, usually will not damage anything, but it will not sound right. If the manual says an input is balanced, use a cable made for balanced signals.

A third use is the insert cable. One TRS plug on one end splits into two TS plugs on the other, carrying send and return for outboard processing on a mixer channel.

XLR: the three-pin lock

XLR connectors have three pins and a latch that locks the plug into the socket. Pin 1 is the shield or ground, pin 2 is the signal (hot), and pin 3 is the inverted copy of the signal (cold). That is a balanced connection, so XLR cables resist noise very well over long distances, and the latch keeps them from being pulled out on stage.

XLR is the standard for microphones. By convention, devices that output audio, such as a microphone, have male connectors, and devices that receive audio, such as a mixer input, have female connectors. A microphone cable is female on the end that plugs into the mic and male on the end that plugs into the mixer.

XLR is also used for other jobs. Lighting gear often uses 3-pin and 5-pin XLR for DMX control data, which needs a different type of cable. See DMX cable vs mic cable before you reuse one for the other. Condenser microphones also get power through XLR cables, which is covered in phantom power explained.

What about 3.5 mm plugs?

The small 3.5 mm (1/8 inch) plug comes in the same TS and TRS versions. Headphone jacks on phones and laptops are TRS stereo, or TRRS if they also carry a microphone signal. The principle is the same as the larger plugs, just smaller.

Which cable do I need?

When two pieces of gear use different connectors, an adapter is not always the safest fix. Converting between balanced and unbalanced connections needs a little care, and a DI box is often the better tool when the cable run is long.