You finally finish wiring up your pedalboard - after it took 3 times longer than expected - you plug in to test the finished masterpiece and what you hear is enough to deflate even the biggest optimist.  You've got a noisy pedalboard. 

What's causing it?  

Today, we're going to get into possible causes of pedalboard noise and how to fix these issues once and for all! 

There are a few main causes of noise in a guitar rig. Some are easier to fix than others.  Some have no easy fix, others do.  

Some of the most common culprits are: 

Lighting interacting with your guitar pickups 
Ground loops on the guitar and pedalboard
Bad power (on your board or at the venue) 
Bad cables 
Noisy pedals & amps 
Interference 
Hearing loop systems

There is a lot to cover here, but if you're reading this you probably want to jump to the quick fix and get some tests going, so we won't get too far into the weeds.

LIGHTING & GUITAR PICKUPS

Depending on the venue you play at, lighting is going to become a consideration for possible causes of noise.  Depending on the type of lighting you're near in the venue, your guitar pickups may pickup extra noise due to large magnets in certain lights, fluorescent lights that are turned on, dimmers, certain LED lights and a few others scenarios that can cause quite substantial noise in your rig. 

The good news - this is venue dependant and shouldn't follow you to the next venue (assuming lighting is different). 

The bad news - at this venue, the problem isn't going away without some troubleshooting. 

POSSIBLE CAUSES

LED lighting
Fluorescent lights 
Movers (lights that move by remote control)
Lighting dimmers
Computer screens
Amp transformers (if you're very close to them) can cause similar noises 
Internal ground loop on the guitar (see the Ground Loop section for this one) 

TESTS 

1. Roll your guitars volume pot to 'off' so no signal is leaving your guitar.  If the noise goes away, chances are you're getting pickup interaction with something close by.  Lighting / EMF is the usual suspect here. 

2. You can also rotate 360degrees (Spin around like a slow moving top) with your guitar volume on (sending signal), there will be 1 or 2 quiet spots (typically) in your rotation.  Again, this is pointing to lighting / electro-magnetic interference. 

3. If you're in a practice room or at home (somewhere where you can control the lighting easily), turn off all the lights and see if the noise goes away or significantly drops.  In larger venues, talk with the lighting operator and see if you can get him/her to turn off all the lights and one section at a time bring them back on (using dimmers to do so if applicable).

4. If you're using a single coil guitar with an out of phase position (Position 2 and 4 on a strat), go to those positions and see if the buzz get's significantly quieter.  Or if your guitar has a humbucker and single coil, switch to the humbucker to see if the noise drops in volume.

POSSIBLE FIXES FOR LIGHTING RELATED NOISE & INTERFERENCE 

1. For lighting related noise, try changing guitars to something with humbuckers or noiseless pickups.  Traditional single coil pickups can't deal with electro-magnetic interference like humbuckers or noiseless pickups can.  Although they most likely won't get rid of a loud, lighting induced hum entirely, they will generally drop the noise floor significantly. 

2. If it's an option, move your position on stage as far away from the culprit as possible.  Yes - if this means moving front and center, it's what's needed.  Do it with confidence, your time has finally come. (This is when you ask for a stage fan to blow your hair out of your face).   

3. Make sure - venue permitting - your audio (amp, pedalboard etc) is not plugged into the same power as lighting.  This is more complicated than just picking a different wall socket.  The venue needs to have separate power dedicated to audio and lighting. 

4. Modify / shield your guitar - You can put copper 'sheets' into the pickup cavity of your guitar.  This is a last ditch effort and does not come recommended by me.  I've had customers do this with some positive results, but it's a high effort, meticulous solution for mixed results at best and is not something you can do quickly on the day of a gig.  You can also switch your pickups to noiseless variations if you have single coils currently in your guitar.

5. Noise gate - Again, not my first choice, but sometimes desperate times call for desperate measures.  A noise gate won't actually get rid of the noise.  It will just 'mute' your guitar when you're not playing.  Once you play and your signal reaches a threshold set by you, your signal turns on and your guitar (and the noise) can be heard again.  This simply removes the noise in quiet moments.  

GROUND LOOPS

 

All of these noise issues are frustrating.  Including this one.  

A ground loop is also referred to as 60 cycle hum in N.America as that's the AC power frequency (60Hz).  In Australia, where alternating current is 50Hz, it's not called 50 cycle hum... Doesn't have the same ring to it I guess. 

A ground loop is caused when you have a voltage difference between two grounds in your rig.  In a perfect world, all ground voltages in a building are going to be exactly the same.  This unfortunately isn't always the case.

In guitar rigs you will typically get a ground loop when you are running 2 or more guitar amps - although a ground loop is not limited to this one scenario.

The main thing to remember is that ground loops are typically venue dependent.  You could bring your pedalboard and two amps to gig one, have a perfectly quiet rig and then you show up to gig 2 at a new venue and you've got a loud buzz in your rig.  

A ground loop that is not venue dependant is often an internal ground loop or grounding issue in your guitar.  More on this in the 'tests' section below.  This is a frustrating one, but any good luthier or guitar tech should be able to get this diagnosed and fixed rather quickly. 

It's also possible to get a ground loop when you're running 4 cable method; using your amps FX Loop.  This is a 1 amp setup, but can still be a culprit for ground loops. Often this is a difference or conflict between your preamp (FX Send) and your power amp (FX Return) and patching effects between these two points in your amp.

The other cause, which has become more prevalent in the last few years is a ground loop in the midi chain of a pedalboard.  Some companies like strymon, meris and others don't isolate their midi 1/4" inputs.  They aren't being lazy or cheap, but this is necessary to make the jack multi-functional - allowing for midi, expression and external switches on the one jack.  

If you're using pedals with 5 pin midi connections (DIN connectors) you don't need to worry about this being the cause.  If you have a 1/4" or 1/8" midi input that can be used for multiple purposes, then make sure you ask the manufacturer if their midi input is optically isolated on that pedal.  Chances are it's not and you'll need to make some smart decisions when planning out your midi chain. 

POSSIBLE CAUSES

1. Internal ground loop on your guitar.

2. Plugging into the same power outlet as your computer and other hardware (laptops are especially bad for this.)

3. Running more than one amp or

4. Using your amps FX Loop

5. Shared power with other electronic devices or lighting

6. Not optically isolating your midi chain.  

TESTS

1. First let's see if we can narrow this down to an internal guitar ground loop or a multi-amp ground loop. Turn your guitar volume pot off, the noise will still be present if the ground loop is caused by your pedalboard and amps.  If the noise disappears, it's typically something going on with your guitar pickups or internal wiring.  If the noise went away when doing this, read test 2 below.

2. You may have an internal guitar grounding issue or lighting interference.  Keep your volume pot on and touch your strings.  If the noise goes away, you most likely have a grounding issue that needs to be resolved on your guitar.  Plug straight into your amp and re-test to be sure (get rid of the pedalboard in your signal chain).  Before jumping to conclusions, read point one of this blog around lighting and guitar pickups.  It could be either at this point! If the noise follows you to every venue, regardless of lighting setup, I'd start by checking the guitar before lighting. 

3. If you suspect a ground loop due to running multiple amps, test is by unplugging all but 1 amp.  If the noise goes away, it's probably a ground loop.  To make sure, plug into amp 2 and unplug amp 1.  See if the noise goes away again.  If the noise is only present when using multiple amps, you've got a ground loop. 

4. If using 4 cable method (your amps FX loop), try running everything to the amp input only.  Make sure the amp is running on a clean channel. Does the noise go away?  If yes, bridge the FX Send and Return with a short patch cable.  Is the noise still gone? Chances are you have a ground loop if you answered yes. 

5. It's worth checking shared power with other electronic devices such as your computer.  Unplug your computers power cable (and any other suspicious hardware) and see if the noise goes away.  

6. For possible midi ground loops.  Unplug all 1/4" and 1/8" midi inputs on your pedalboard.  Does the noise go away? 

POSSIBLE FIXES

1. For internal ground loops on the guitar, a quick at-the-gig fix is to always make sure you're touching your strings or bridge so your guitar is grounded to your skin.  A longer term solution is to bring your guitar in to a tech and get them to check it out.  I'd make sure the guitar is showing symptoms in multiple venues to confirm you aren't getting this mixed up with lighting interference.  

2. For multi-amp rigs: Isolate all of your guitar amps, except for 1 with an audio transformer.  This is the easiest and safest way to do it.  Something like Buzzkill is designed for this purpose and also gives you polarity inversion / phase correction in case your amps are out of phase with each other (an unrelated, but equally frustrating issue). 

3. If it's looking like you have a ground loop between amps, check out the Ebtech Hum X.  Instead of isolating the audio path, you can isolate the power sending to the amp itself.  I've gotten mixed reviews from customers on this unit.  For most the Buzzkill works better, for others the Hum X does a good enough job and can save you a few dollars.   

4. For amp FX Loop noise: Use Buzzkill on the FX return.  To do this, from your last wet pedal (in the FX loop), plug into Buzzkills input.  Buzzkills output sends to the FX return.  See if that fixes the issue.  You can also try Buzzkill the FX send before you hit any pedals in your FX loop. 

5. For shared power issues, try a different wall socket or try isolating that power output to your rig.  Often if it's a quick session for me, I'll run my laptop on battery power and that can fix the issue quickly.  For longer sessions where this work-around isn't ideal, I'd try isolating the power to your guitar rig.

6. For midi related ground loops you want a midi splitter.  Not any midi splitter will do though.  Some units, like the Disaster Area Midi Box 4 only optically isolates it's main midi input.  If you're running more than one 1/4" midi device, this unit is no longer isolating your entire midi chain.  You want a midi box that isolates the individual 1/4" or 1/8" midi outs like a Strymon Conduit or Morningstar Midi Box

HIGH GAIN AMPS & FX LOOPS 

High gain amps tend to be a noise haven for guitar rigs.  It's not necessarily your amps fault, don't be angry.  The gain required to overdrive your signal is the same gain that will bring your noise floor up to higher levels.  

If you're playing a channel switching amp or high gain pedals, stacking multiple drives, distortions and fuzz pedals you will experience a louder hum in your signal path.  

What can you do about it? 

POSSIBLE CAUSES

1. High gain pedals or amp channels. If you're running very high gain sounds in your pedalboard or amps, you will get a higher noise floor.  

2. Pairing high gain with compression.  If you're running a compressor and high gain, the compressor will also raise your noise floor since it's bringing the quiet moments of your playing even higher.  

3. If you're running your amps FX loop, you could be getting amp noise and a ground loop.  See Ground Loops (previous point) for more info. 

TESTS

1. To test for noisy pedals, keep your amp running loud, but turn off your gain pedals and compression.  If the noise goes away or significantly drops, chances are your gain pedals and/or amp channels are the culprit. 

2. For an amp FX Loop test, try keeping your normal, high gain sound on, bypass your amps FX Loop (run your whole pedalboard signal chain into the amp input) and see if the noise significantly drops.  

POSSIBLE FIXES

1. If noisy pedals are the problem (whether an overdrive, fuzz or compressor) I'd reluctantly recommend a noise gate pedal. It's not my favourite thing to do, but in this instance, I think it's warranted.  There isn't much else you can do to correct a noise floor issue caused by high gain pedals other than changing your genre of music, or using a noise gate.  Something like an MXR Smart Gate or Boss NS2 Noise Suppressor are great places to start!

To be clear, the only reason I'm reluctant to recommend noise gates is they are a bandaid, not a fix.  But when you don't have a clear fix, you need a bandaid.  

2. One important point here just to be extra sure on the pedal front.  I would run any noisy pedals at a lower gain (as clean as possible) just to make sure there isn't a fault with the pedal.  This is very unlikely, but worth checking.  If the excessive noise is still present when the pedal is clean, it's possible you have a faulty pedal.  Swap the pedals in question out for a different unit and re-test.

3. If you bypass your amps FX Loop and the noise significantly drops, see Ground Loops (previous point) in this blog for more info on what to do next.  If you have or can borrow another amp with an FX Loop, try that as well for the sake of the test. 

BAD CABLES

 

Bad cables believe it or not can cause excess noise in your rig.  The amount of times I've had customers order from our Soldered Cable Shop, install them on their rig and come back with, "I can't believe how quiet my pedalboard is now" is enough to make me blush - and I don't blush easily.

To be clear.  This is not because Goodwood cables have any magic sauce on them.  There are a bunch of companies that make great patch cables.  These customers were either using cables with inferior shielding / noise rejection or they had some intermittent cables that were wreaking havoc in their rig. 

POSSIBLE CAUSES

1. If you are running a lot of pedals on your pedalboard (and therefore a lot of cables), you may be adding a little bit of noise per cable.  A small amount of noise across many cables can add up to a noisy rig - especially if the cables are not shielded well. 

2. A bad patch cable can also cause noise.  If you have a cable that has a partial short (faulty) or some other internal issue, it can also cause noise.  

3. If you're experiencing a crackle or intermittent signal loss, you may also have a bad cable or dirty connections. 

TESTS

 1. I'd start by cutting your board in half.  Not literally! Cut your signal chain in half.  Plug your guitar in where you normally would, then after a couple of overdrive pedals, send signal to your amp.  Now you're only running a few pedals into your amp rather than your whole signal chain.  Reassess the noise from here.  Has it significantly reduced? 

2. Again I'd start by eliminating pedals in your signal chain.  If you hear a significant improvement more than a subtle one, you may have a faulty pedal or cable.  Try the first half of your signal chain and then the second half (plug into your first modulation pedal with your guitar and out to your amp after your last pedal as normal) and see if one half is significantly worse than the other.  Start testing one cable and pedal at a time on the worst half first.  

3. Rotate the cables in your pedals, wiggle them, hit the pedals... Anything to get the connections slightly moving. See if you have any crackles - keeping a delay pedal turned ON while doing this will help! If you get delay trails with crackle you know the issue is before the delay pedal.  If you don't get any crackle on your repeats (really, you shouldn't get any repeats at all), you know the crackle is coming after the delay pedal.  

POSSIBLE FIXES

1. If it seems like the noise is increasing slightly with every cable that is being added to your board, then it might be time to upgrade your cables to something with a half decent shield.  Since I would never want you to spend money on cables unnecessarily, feel free to email us first or talk to a pedalboard expert in your area that has experience here and get a second opinion.  As you can see, there are many causes of noise in a rig.  You want to be sure you're investing in the fix rather than a shot in the dark. 

2. If I was suspicious of a faulty cable on my board, I'd again start with the half of the signal chain (see "Tests" above) that seemed to have the worst noise or signal loss and would temporarily replace one cable at a time and re-test.  If one cable replacement yields positive results, you've found your culprit.  If none of the cables get you the results you want, I'd start by eliminating one pedal at a time and seeing if you can point to the issue that way.  It's also possible a pedal is causing the excessive noise or signal loss! 

3. If you find noise when rotating cables in their jacks or hitting a footswitch on a pedal, this can be quite an easy fix.  There is always a chance you have a bad cable or switch that needs to be replaced, but more than likely you have a dirty connection on a jack, plug, power cable or switch. 

There are three areas to focus on here.  First let's start with the pedal jacks and cables.

Get some electrical contact cleaner (make sure it's make for electrical contacts like DeOxit D5), spray it in your pedals input jack, plug that cable you'll be using in and out 10-20 times immediately. Repeat for the output jack as well.  This should get it clean enough to retest and see if it was a dirty connection or not.  You can do the same for DC power jacks as well (without running power to your pedalboard). If your problems go away - great! 

If you are using pedals with 3PDT switches (these are the foot switches with a loud 'clunk' rather than a soft tap).  You can also spray contact cleaner inside the switch (where the plunger meets the switch) and cycle the switch 10-20 times immediately after.  Re-test.  For soft touch switches (no click) contact cleaner usually won't help with noise issues as these foot switches are not typically in your audio path. It won't hurt to try though just in case it is for your pedal. 

Contact cleaner is a must have for any electric guitar player.  Use it on dirty pots, guitar jacks, DC power etc. It can fix all sorts of issues in a rig.  Always have a bottle with you in your gig bag! 

WIRELESS SYSTEMS & INTERFERENCE 

Wireless frequencies can also cause noise in a rig.  I'm sure we've all experienced our mobile phones causing noise in our rig when we practice guitar.  Often times we don't experience any downsides with wireless signals as they are often so far out of the audio range it's not an issue.  However there have been certain circumstances I've come across myself or with customers that are worth mentioning.  

The most recent was a customer that was getting radio frequencies in his rig at one venue, but couldn't pin point it to anything obvious.  After quite some time of troubleshooting he found out it was a hearing loop installed at the venue that wasn't installed properly.  Essentially a hearing loop sends a signal (usually what is happening on stage) directly to the telecoil in audience member hearing aids.  You need to make sure these frequencies are blocked from coming onto the stage (and interfering with things like guitar pickups).  The stage should be a 'dead zone' for the hearing loop.  This didn't happen at that particular venue. 

Poorly grounded / shielded guitars can also be more susceptible to radio frequencies. 

POSSIBLE CAUSES

1. Hearing loop that was not properly installed at the venue. 

2. Poorly grounded or poorly shielded guitar. 

3. Wireless gear set to conflicting frequencies.  This is least likely as these frequencies are well out of audio range, but worth checking if all other tests don't pan out. 

TESTS

1. Turn off the hearing loop and see if the noise goes away. 

2. Switch guitars and see if the noise disappears. 

3. Turn off wireless mics, transmitters and wireless guitar systems.  If the noise goes away, turn them back on one at a time to find the culprit.  

POSSIBLE FIXES

1. If turning off the hearing loop system fixes the problem, make sure the stage is blocked from hearing loop frequencies. The stage needs to be a hearing loop dead spot.  How do you do this? Not a clue - but your local hearing loop specialist will be able to help you out with this.  

2. If you switch guitars and the noise goes away, phone up your luthier or guitar tech.  Tell them your guitar symptoms and tests you've done.  Ask them if they have a suggestion for a fix. 

3. If you've narrowed down the issue to a wireless unit, work with the venues sound tech to check out the wireless unit and frequency settings.  Don't pick any random frequency. Make sure to choose one that is not in use and won't cause further problems.  If the unit is faulty - prepare yourself to deliver the bad news to the person who is now going to be using and instrument lead for that gig.  

 

This by no means covers every single cause of noise in a guitar rig, but it's definitely covering the majority.  The amount of times I thought I had everything noise related covered in a rig and then a new problem rears it's ugly head - it's staggering.  Guitar rigs are frustrating to troubleshoot, especially when you're doing everything right! But gear fails, noises appear, venues change and you need to have the tools to tackle these problems! 

Send us an email if you've got questions, stories or fixes we didn't cover! 
info@goodwoodaudio.com