Dealing with noise (part 1)
Noise is every guitarists’ worst enemy. We’ve all experienced hissing, buzz, crackle and hum. It’s frustrating but there are many things you can do to reduce noise to a minimum. In this first of two articles we’ll look at the basics, the reasons for noise and how to solve the problem.
I often get asked ”why is David’s guitar dead quiet while mine is hissing like hell?” David’s guitar is certainly not as silent as it may appear. If you’ve ever listened to a bootleg or had the chance to see him live, you’d noticed that his rig is far from silent. However, he might be dealing with other issues than you. Let’s start with some basics.
Noise is mainly caused by two things – outside interference and noisy components (usually a combination of both). Outside interference is electrical radiation being picked up by almost any component in your rig mostly due to lack of proper ground and/or shielding. Noise caused by the components them selves is often as a result of cheap or faulty parts, bad assembly etc.
- Make sure your guitar and amp is connected to ground that has a clear path out of your house in into ground.
– Check every cable (instrument, patch and speaker) for bad connections and plugs.
– Make sure that no instrument or patch cable is touching any power cables.
– Check every power supply for bad connections and make sure they’re not overloaded.
– Switch off any nearby computers and assigned electrical components, radios and stereo units, cell phones and efflorescent lights.
– If possible, make sure that your amp and pedal board runs on a separate power circuit than your TV, computer, refrigerator, light rig etc.
– Be tough on your pedal board and ditch any overly noisy pedal.
Ground is what the name implies – a connection to the earth. In case of a power failure or short circuit, the ground connection will lead the electricity out of your rig, through the wall and outside into the ground, rather than the electricity going through your body, which is a substantial conductor. We’ve all heard stories about musicians being fried or shocked on stage, and although this may sound cool, it can be very serious so the ground connecting is there to avoid this.
You’ve probably experienced hearing this loud buzzing from your guitar and if you touch any of its metal parts, the buzz will change in volume and/or pitch. This indicates that there’s a bad ground connection somewhere that needs to be fixed. Unscrew the pickguard, check all ground cables and make sure they’re connected to the right parts. If the buzz is still there you need to check the power outlets to your amp and pedal board.
US power cable plugs has three pins and the lower round one is ground. Some musicians cut this one off, because the plug won’t fit into all outlets but this means you’ve cut the ground, which is like asking for trouble. As a touring musician you should always carry a converter plug (with ground) that fits into any outlet. Most European plugs have two pins with ground in the plug it self (usually two metal strips) but in any case, make sure that all extension cables have ground! The best way to check this is to always keep a circuit tester ($20 at hardware stores) in your utility kit. Plug it into the socket and check the ground connection.
The word shielding is a bit misleading and often misunderstood. It does not mean that you’re shielding your guitar from an outside source with a protective layer but a shield (like copper foil) will gather the outside electrical interference that’s causing the noise and drain it out of your guitar. For this to work, you need to make sure the shielding is connected to ground (a cable that’s either connected directly to the output jack or via a tone pot that’s again connected to the output jack) or else it will have no place to drain the noise and it won’t have any effect. In some cases your noise problems will be eliminated with a proper shielding but it will only help for some types of interference (certain frequencies) and it’s by no means a miracle cure.
60 cycle hum
60 cycle hum (or 60hz) is a loud, low frequency buzz coming from your guitar. Bad ground connection is consistent but 60 cycle hum is directional and if you walk around the room it will come and go depending on the radiation field. This kind of noise is caused by outside electrical interference and it may come from a nearby transformer, light rig, your kitchen or just about anything. Now, shielding your guitar won’t eliminate this kind of noise because it’s picked up by the pickups. Vintage style single coil pickups have magnetic poles that are exposed to any outside interference so they’re basically acting like antennas. In case you experience 60 cycle hum, you need to locate the source and switch it off if that’s possible (computers, lights, TVs, refrigerators etc) or, in case you’re on a stage (interference from ligh rigs, power sources, PA systems etc) try to find a separate power circuit.
Humbuckers and so-called “noiseless single coils” are less subjected to this kind of noise, or noise in general. Humbuckers aren’t ideal for recreating David’s tones and those of us that swear by our vintage style single coils may find it easier to live with a compromise but it’s well worth checking out EMG, Lace Sensor, Fender Noiseless, Kinman, Barden etc. Most guitarists will agree that these does not sound like vintage style single coils like Fender CS69, Duncan SSL5 etc, they lack some of that bite, the crisp top and character, but that’s ultimately down to taste.
Guitars and pickups
As we’ve talked about, a proper ground connection and shielding is vital for keeping your guitar as silent. I’ve had great success with shielding the pickup cavity of my guitars with copper foil but then again, I’m lucky to rarely encounter 60 cycle hum or bad ground connections. Again, vintage style single coil pickups is a compromise no matter what and you are bound to have some level of noise because the pickups will pickup electrical interference in addition to your strings.
From time to time you may also experience a pickup that’s microphonic. This is easy to detect as one or more of the pickups will be feeding uncontrollably and insanely loud (not to be confused with natural feedback). This means that some of the parts inside the pickup are loose and you need to pot it – reassemble the pickup and dip it in wax to keep all the parts in place. This is a complex operation so in most cases you’re better off buying a new pickup (or returning your guitar if it’s brand new).
Amps are no different from any other component in your rig but slightly more difficult to deal with and in case you’re not trained in electronics I strongly advice you to take your amp to a trained technician. Replacing a tube is easy but if you start to poke around you might end up with a serious electrical shock… worst-case death.
Assuming that your amp is properly grounded, the most common reason for noise is bad tubes, loose parts or parts that needs to be replaced. Check both the head and cab for loose construction and cracks in the wood, loose screws, dying tubes, wires etc. Old transformers and leaking/dry caps will add noise but also cause irregular current in the amp, which is not good for neither the tone nor the components, so make sure you take your amp to a tech and have this checked once in a while.
In case of microphonic tubes you might hear a vague hollow ringing coming from your amp. This is typical for a tube that’s been shaken up a bit from vibrations in the chassis and it’s time to replace the tube. If you’re unsure you can use a wooded stick (remember that metal is a conductor and should never be used!) and tap gently on the tube. If it sounds like you’re picking a rubber band it means that the tube is broken.
Again, assuming that the ground is OK and your guitar and amp is working properly with the needed shielding, it’s time to look at the signal line.
Cables acts as long antennas picking up electrical radiation, radio waves etc within a fairly vast range. Cheap instrument and patch cables are not shielded (or not shielded properly) and as you now have learned, there’s nothing to drain the interference that’s causing the noise out of the signal path. So the moral is – get good quality shielded cables!
Length is also a factor. No matter how good the cable is, the longer it is the more it will drain your signal. A 20ft instrument cable should be more than enough for most setups. I swear by my Evidence Audio Melody cables (David’s choice since 2005). I also recommend Lava, Planet Waves, George L’s, ProCo and Mogami.
Patch cables are often overlooked and one tends to use whatever’s convenient. Those multi packs with different coloured cables are strictly forbidden! Make sure all your pedals are connected to good quality patch cables that are cut as short as possible. You want to connect the pedals not clutter your board. Again, length is crucial and although your board might include only the average of 10-12 pedals, small cables can turn up to be pretty long if you add them up. George L’s, Lava Mini and Evidence Audio Monorails are ideal for boards that are frequently rearranged.
Speaker cables are perhaps even more overlooked than patch cables. Hands in the air those of you who’s never used an instrument cable between the head and speaker cab… Instrument cables are not designed for this and in worst case you might overload the cable and short-circuit the amp. Be sure to use dedicated speaker cables that are designed for more power. I strongly recommend the Evidence Audio Siren for this.
I don’t mean that you have to spend all your savings on expensive cables but keep in mind that although it’s no fun getting a cable over a pedal, it often pays off putting a little extra into it. The reason why your new pedal may sound like shit might be the cables that are attached to it. Check out this Q&A with Tony Farinella from Evidence Audio for more about the importance of good cables.
Feeding the right power to your pedals is crucial for eliminating noise. The wrong voltage or the wrong use of power supplies can be the main source of your frustration. A pedal board with 10-12 pedals is often hooked up to 1-2 Boss 9V adapters with most the pedals in a chain. One pedal might need a separate 18V adapter and perhaps 1-2 vintage pedals are running on battery. Batteries are noisy by nature but that’s a compromise most of us are willing to take to get that old fuzz pedal warm and smooth. Some pedals like digital delay processors are often a bit more demanding than the average overdrive and might start to distort and hiss if you place them in a power chain with other pedals. The more adaptors you keep the more they require your attention and you shouldn’t take the risk of one of them not working in the middle of a show.
The best way to power your pedals is to use one unit dedicated to power as many pedals as possible. Voodoo Lab, Cioks and T-Rex (among others) offer power supplies in all shapes and variations depending on how big your pedal board is. Each unit has separate lines for each pedal for a more consistent signal. Some of the bigger models also allow different voltages so that you can use all your pedals on one unit.
Don’t forget the power cable to your amp! Older amps often have chords that looks like a curled up snake or worse. These should be replaced immediately. Not only for noise issues but you don’t want to get an electrical shock sent through your body next time you’re unplugging your amp. A good quality power cable ensures the correct current to your amp, which again means less noise and less wear on the parts. Check out the Source from Evidence Audio or simply take your amp to a skilled technician and have him replace the old cable with a new.
It’s impossible to cover everything but I hope this answered some of your questions. Please feel free to use the comment field and share your tips and experience! Next time we’ll look at pedal boards and how to tweak your favourite tone without frustrating noise problems.