03Fix your rig

Why does my guitar signal cut out or crackle?

Updated · By the Suede Social desk

The answer

Usually it is a cable or a jack. Swap your instrument cable first. Then play a note and gently wiggle each cable end and jack, one at a time; the one that crackles is the culprit. After that, check the guitar’s output jack, tired batteries, scratchy knobs and worn footswitches, in that order.

On stage right now?

Grab your spare cable, plug the guitar straight into the amp, finish the set, and troubleshoot at soundcheck.

Match the symptom

When the noise happens tells you where it lives.

Crackles when a cable moves
A cable or a jack. Run the wiggle test below.
Crackles when you turn a knob or flip the selector
A dirty pot or switch. Clean it with electronics contact cleaner.
Sputters, then fades out
A dying battery, in a pedal or in active pickups.
Pops when you stomp a pedal
A switching pop. See “Pops when you stomp” below.
A digital pedal reboots mid-song
Not enough current on its power output.

Checks, cheapest first

  1. 01Swap the instrument cableThe cable from your guitar takes the most abuse: stepped on, yanked and coiled tight. Swap it for one you trust before testing anything else.
  2. 02Run the wiggle testSet the amp to a moderate volume, let a note ring, and gently wiggle each cable end and jack, one at a time. A crackle or dropout marks the fault. Include the send and return jacks if you use your amp’s effects loop. Patch cables with solderless plugs can loosen over time, so reseat or replace them.
  3. 03Check the guitar’s output jackIf wiggling the plug in the guitar crackles, the jack is loose or its contact has lost its grip. Tighten the outer nut while holding the jack still, because a jack that spins twists and breaks its wires. A worn jack is a quick swap for a tech.
  4. 04Rule out batteriesA dying battery makes a pedal sputter, gate or fade out. Active pickups and guitars with an onboard preamp run on batteries too, and a flat one sounds weak, distorted or silent.
  5. 05Clean scratchy knobs and switchesCrackle when you turn a knob or flip the pickup selector means dust or oxidation inside. Spray a little electronics contact cleaner into the pot or switch and work it back and forth.
  6. 06Check the powerA digital pedal that reboots or drops out mid-song is often short on current. Give it its own output with enough mA, and check the numbers in the power planner.
  7. 07Test the footswitchIf the signal cuts in and out as you press a pedal’s switch, or only works in one position, the footswitch is worn. Footswitches are wear parts, and a tech replaces them routinely.
  8. 08Rule out the wirelessOn a wireless system? Charge or swap its batteries and keep a clear line of sight between the transmitter and the receiver. Then test with a cable to rule it out.
  9. 09Then look at the ampEverything swapped and the amp still crackles or cuts out? Clean its effects loop jacks first. On many amps the signal runs through the return jack even with nothing plugged in, and dirty contacts there crackle and drop out. Work a cable in and out of the send and return jacks a few times, or spray them with electronics contact cleaner. Still crackling with nothing plugged into the input? The fault is in the amp. In a tube amp, a failing tube is a common cause. Take it to a tech, and do not open a tube amp yourself: its capacitors hold dangerous voltage even when it is unplugged.

Pops when you stomp

A pop when you switch a pedal on or off is common with true-bypass pedals. A small DC charge builds up on the pedal’s input or output capacitor and discharges when the switch moves. A tech can fit a pulldown resistor, which drains that charge and stops the pop.

Turn the amp’s volume down before you plug or unplug cables. A live jack pops loudly through the speaker.

Common mistakes

  • Changing three things at once. Change one thing, test, then change the next.
  • Letting the output jack spin while you tighten it, which twists the wires inside.
  • Spraying a general-purpose lubricant into pots. Use contact cleaner made for electronics.
  • Wrapping cables tightly around your elbow. That kinks the wires in the same spots until they break. Coil them loosely, over-under style.
  • Opening a tube amp. Leave it to a tech.

Words used here

Instrument cable
The long cable from your guitar to your first pedal or the amp.
Patch cable
A short cable linking one pedal to the next.
Jack
The socket a cable plugs into.
Pot
Short for potentiometer: the part behind each volume or tone knob.
Effects loop
Send and return jacks on an amp that place pedals after its preamp.
Contact cleaner
A spray made for electronics that clears dust and oxidation from pots, switches and jacks.
Pulldown resistor
A resistor that drains stray DC charge from a pedal so it switches without a pop.
Active pickups
Pickups with a built-in preamp, powered by a battery inside the guitar.

Tools for this

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