Is it fret buzz or electrical hum?

The ten-second test

Listen first. The kind of noise tells you which guide you need.

You hear it unplugged

Fret buzz. A string is touching a fret it should clear. Work through the checks below.

It is there while nothing is ringing

Electrical. Go to the pedalboard hum guide.

It drops when you touch the strings

Electrical, and the drop is normal: your body helps ground the guitar.

A rattle on one or two notes

Something loose vibrating along: a tuner nut, a strap button, a pickup screw, the output jack nut, or something in the room.

Checks, cheapest first

1. 01Check your fretting handPress just behind the fret: not on top of it, and not in the middle of the gap. Pressing too far back from the fret is a classic source of buzz.
2. 02Ease off the pickEvery guitar buzzes if you dig in hard enough. If the buzz only shows up when you hit hard, lighten your attack or raise the action a little.
3. 03Find where it buzzesWhere the buzz lives tells you the cause. Use the map under these checks, then come back to the matching fix.
4. 04Think about what changedA new string gauge, a different tuning or a change of season all move the neck. Lighter strings and lower tunings mean less tension, and dry winters and humid summers shift neck relief. A guitar that played clean last month can buzz today with nothing broken.
5. 05Check the neck reliefTune to pitch, put a capo on the first fret, and hold the low E string down at the last fret. Check the gap between the string and the top of the 8th fret. A typical target is about 0.25 mm (0.010 in), roughly the thickness of a business card. No gap means the neck is dead straight or bowed back, which buzzes in the first few frets. Your maker’s setup guide gives the exact figure for your guitar.
6. 06Adjust the truss rod in small stepsThe truss rod sets relief, not string height. On most guitars, turning the adjusting nut clockwise as you face it tightens the rod and reduces relief; counterclockwise loosens it and adds relief. Turn a quarter turn at a time, retune, let the neck settle, then measure again. If the rod feels stuck or very tight, stop and take it to a tech.
7. 07Raise the action at the bridgeRelief right and still buzzing everywhere? Raise the saddles or the bridge a little at a time until the buzz clears at your normal attack. Check the intonation after a big change.
8. 08Book a setupBuzz on one or two frets only, open strings buzzing, worn grooves in the frets, or a truss rod that will not turn: these are jobs for a tech. A setup is routine work for any guitar tech, and uneven frets get a fret level and crown as well.

Where it buzzes, and why

Open strings only

A nut slot cut too low or worn down. A tech can shim or replace the nut.

The first few frets

Not enough neck relief. A small truss rod adjustment usually fixes it.

One or two frets only

A high or loose fret, usually the one just above the note that buzzes. A tech job.

High up the neck only

Uneven frets near the body, or action set too low. A tech can level the frets.

Everywhere

Action too low for how hard you play. Raise the bridge saddles a little.

A little buzz is normal

Low action and a little buzz go together. If you hear a faint buzz unplugged but not through the amp at your normal volume, plenty of players leave it alone. What the audience hears is what comes out of the speaker.

Common mistakes

• Cranking the truss rod to lower the action. The rod sets relief. Action is set at the bridge.
• Turning the truss rod in big turns. A quarter turn at a time, then let the neck settle.
• Blaming the guitar after a string change. A new gauge or tuning changes the tension, and a setup brings it back.
• Chasing electrical hum with a truss rod. If the noise is there while the strings are silent, it is electrical.

Words used here

Fret buzz

A rattle when a vibrating string touches a fret it should clear.

Action

The height of the strings above the frets.

Neck relief

The slight forward bow in a neck that gives the strings room to vibrate.

Truss rod

An adjustable metal rod inside the neck that sets the relief.

Nut

The slotted piece at the headstock end of the fretboard that the strings rest in.

Intonation

Whether notes up the neck stay in tune with the open strings. Set by the saddle positions.

Setup

A tech’s routine adjustment of relief, action, nut, intonation and pickup height.

Related guides

• How do I stop my pedalboard humming?Hum, buzz, ground loops and digital whine, cheapest check first.→
• Why does my guitar signal cut out or crackle?Crackle, dropouts and switching pops, traced with the wiggle test.→
• What string gauges do I need for a 7-string, 8-string or drop tuning?Heavier gauges for lower tunings, why scale length matters, and the setup after.→
• What guitar pedals should I get first?Tuner, overdrive, then delay or reverb, and why that order works.→