XLR and Instrument Cables

XLR, TRS or TS: what the plug says about the signal

XLR has three pins and carries a balanced signal, two signal conductors plus a shield, which cancels hum over long runs. That is why it is used for microphones and for line connections to mixers and interfaces. A quarter-inch TS plug (tip and sleeve) is unbalanced and made for guitars and keyboards. A quarter-inch TRS plug (tip, ring and sleeve) can be balanced or stereo depending on how it is wired. On a microphone cable the female XLR goes to the mic and the male to the mixer.

Capacitance, shielding and length for guitar cables

A passive guitar pickup is sensitive to the cable it drives. Capacitance, listed in pF per foot, adds up with length and rolls off the high end, so a low-capacitance cable, such as one rated 18 pF per foot, stays brighter on a long run. Shielding matters too: braided and dual-shielded constructions block more noise than a thin spiral. Keep cables as short as the stage allows, and check the plug type at each end, straight or angled, TS or TRS, before you plug into an amp or a pedalboard.

Questions about XLR and Instrument Cables

Can I plug a guitar in with an XLR cable?

Not directly. A guitar puts out a high-impedance, unbalanced signal that needs a TS instrument cable into an instrument input, or a direct box that converts it to a balanced signal. XLR cables are for microphones and balanced line signals.

Is an instrument cable the same as a speaker cable?

No. Instrument cable is shielded and carries a weak signal, while speaker cable is a thicker, unshielded pair that carries amplifier power. An instrument cable between an amp and a speaker cabinet can overheat the thin conductor.

What is the difference between TRS and TS?

A TS plug has two contacts for an unbalanced mono signal. A TRS plug has three contacts and is used for balanced mono, for stereo such as headphones, or for insert cables. They look alike, so check the plug marking.