From the moment the first electric guitar was plugged into an amplifier there was hum…and it’s still driving guitarists to extremes!
And it has pretty much been with us ever since.
Here are a few things to try to help you beat the plague and/or curse that follows us around:
First, try to eliminate any inference of your signal by having your guitar or amp placed too close to a television set, radio, computer monitor, etc. These things cause noise.
Next try to determine if the source of the hum is the guitar, the amp or the cord. This will be done running the guitar directly into the amp, without a pedal board or effects.
Try the cord first. Simply use a different cord. It is great when a fix is this simple.
It can drive you mad. Mad, I say. MAD!
Try a different guitar, and see if the problem persists. If a second guitar still hums after swapping out cables, it is most likely the amp.
Does the amp still hum or buzz without the guitar even being plugged in?
Some amps have a ground switch, and putting that switch in the other position can conquer the issue as simple as that. If the amp is plugged into an outlet this is on the circuit as lights with dimmer switches, it may be best to run an extension cord to a different outlet that’s on a different circuit.
Some older amps with 2-prong power cables may beat the hum buy being unplugged, rotated 180º and re-inserted into the outlet. These older power cords should be replaced with modern 3-prong grounded versions, BTW. Serious shocks, burns and even death by electrocution can result from ungrounded amps. If the amp has a two-pronged cord, a multi-meter should be used to determine if the potential shock exists with the other gear on stage, including the other instruments and the P.A.
[This is serious stuff (you know death and all), get those power cords replaced.]
Sometimes just rotating the amp so it faces a different direction can help. Murphy’s law dictates that this will be the most useless position determined by your needs.
If your amp is connected to a P.A. via the amp’s direct output and you’re experiencing hum, try the ground lift switch (if the amp has one or on the D.I. box if you’re using one). This is such a common experience that the switch is built in for just this reason.
Unfortunately, when components on amps such as tubes, capacitors and resistors start going south they can also start hum and buzz. Sometimes, it is time to take the amp to the shop for a tune up. (And get that 2-prong power chord replaced, too.)
If you determined your guitar is the source is the buzz it is not the end of the world.
If your electric guitar hums when you’re not touching the strings, this is a natural thing. Somewhere in the inner guts of your guitar is a wire (or some other conducting source as on a telecaster) from the controls to the bridge. (it is also the same ground on the cable (and, therefore the amp). So when you touch the strings, your are sharing a common ground with your rig.
If you find touching the jack of your guitar cable eliminates the hum, but touching the strings doesn’t; that grounding wire may have become disconnected. A quick short term fix could be running a little test lead (the kind with the alligator clips on each) from some grounded part of the guitar (such as the leg of a potentiometer that is connected to the back of the potentiometer) to a metal part that touches the strings (such as the bridge or tailpiece).
Usually the internal wire that performs this function is hidden so discreetly it might take a little research to replace or fix it. It doesn’t exist on most Telecasters: The bottom plate of the bridge pickup is grounded, and that is connected to the bridge plate (and the bridge) through the pickup’s height adjustment screws: a simple elegant solution. The grounding wire on a Les Paul is usually attached to the lower insert for the stop tailpiece, but is near the endpin to connect to the tailpiece on Bigsby equipped models…and all of this is done through small holes inside the guitar’s body, hidden from sight.
Interestingly enough, using coated strings, such a Exliers, may prevent you fretting hand from actually touching the metal string (it is coated) so it may buzz. Touching the plain (uncoated) higher strings will conquer the problem, as would resting your hand on the bridge.
Sometimes turning the guitar or facing a certain direction will squelch some of the hum. This technique may be more useful in the studio than playing live, where standing and facing in only one direction may not constitute putting on a killer show.
Guitars with single coil pickups, such a Telecasters, Stratocasters and P-90 equipped Les Paul Specials and Juniors, are more susceptible to hum than other model guitars such as the Les Paul Standard and Custom, and the ES-335 with double coil pickups.
In fact, back in the 50’s the hum of those single coil pickups led to a new design of the double coil pickups: the humbucker. The name says it all. In is most easy to understand form, the pickup uses two coils instead of one (so they are also called dual coil pickups), with the second coil performing a canceling action against the offending humming frequency.
It also cancels some of the twangy, brighter top end of the actual guitar sound, but that is preferred by some players.
Anyway, Humbucker equipped guitars suffer less from the hum affliction.
For those that prefer the single coil sound all is not lost. Most manufactures now use single coil pickup sets that make what can best be described as a humbucker when both pickups are on at the same time.
The idea is that the hum is only a true problem when it is not being covered up by the much louder sound of the guitar actually being played: in between songs, switching the pickup selector to the middle position (with both pickups engaged) no hum, no problem.
For those that are still bothered, there are humbuckers that are single coil-sized and designed to sound more like single coil pickups. Or, you can just living with it…as guitar players have been willing to do for the last 80 or so years.
The Seymour Duncan STK-S4: a humbucker Strat pickup that looks and sounds like a single coil pickup.
Lastly, if you don’t find the source of your hum, you can try an isolation transformer. There are two different kinds. The first, less expensive, option is a unit made for your guitar signal path: units such as the ART DTI Dual Transformer/Isolator which can be had for about 60 bucks. The second and way more expensive option is a unit that operates on the power side of the equation. It is doubtful as a working musician you’d buy one.
The ART DTI Dual Transformer
In truth, sometimes the hum wins. The was one bar gig where we set up and all was quiet, they opened the doors and turned down the lights and…well, I’m not going to insult anyone’s intelligence by finishing the story. But, once the doors were open it was too late for us to fix a problem we didn’t know existed till that point.
And even when you beat it, it will find you again: usually at the least convenient time.