Guitar Effects

Anything that can affect the sound of a guitar can be considered a guitar effect. Most effects start with the volume and tone controls of your guitar. There are many guitars that now feature active EQ, split coil switches, phase switches, and even MIDI output. The types of pickups and electronics used also very much effect the sound of your guitar.

Pickups are simple coils of wire wrapped around a magnet (electro-magnet) and when the string vibrates it causes small changes in the magnetic field which produces a small output signal. There are essentially two types of the guitar pickups namely the single coil, and the double coil, also known as a humbucker. There are numerous types of single coil pickups but for the most part they have a bell like sound that is thinner sounding than double coil. They are more prone to noise especially the 60 cycle hum as well as fluorescent lights and light dimmers. They sound great for rhythm and lead. Some guitarists who use single coil pickups are Jimi Hendrix, David Gilmore, and Eric Clapton. The double coil pickup or Humbucker is louder and is less succepable to noise and has a more full rich sound. Guitarists who use double coil pickups are Jimi Page, Slash, Robert Fripp and many others. Changing the pickups in your current guitar should be done by someone who knows how to change out a pickup. There are a number of alternative pickup manufacturers like DiMarzio and Seymour Duncan.

Strings can also affect the sound of your guitar. The type of material used in the string is important. Stainless Steel strings produce a bright tone and have anti-corrosive characteristics. Nickel-plated Steel strings are bright and highly magnetic, which is a good thing. Strings made of pure nickel have a full more rounded tone.

Picks – The type of pick and the way the string is played affects the sound of the guitar. There are a wide variety of picks that range from very thin to very thick. Each thickness and shape produces a slightly different tone. This is one of the more subjective areas in creating your own guitar tone. There are a number of factors that the guitarist can do in this area to change the tone. There are also many guitarists who don’t use a pick at all. These include Mark Knopfler, Robben Ford, and even Jeff Beck.

Guitar Sustainers are a device that is usually placed on or near the strings of the guitar where it causes the string to vibrate. The guitarist then simply moves his finger along the string from fret to fret. They have a fluid sound that is similar to that of a violin. Some guitar sustainers included are the EBow, and Fernandes Sustainer.

Guitar Amplifier

Next we finally arrive at one of the more potent guitar effects which is the guitar amp. There are many guitarists who actually use the cleanest amp they can find and then run guitar modifiers (pedals, rackmount delays, and digital effects) in to the amp. The size (Wattage, Speaker Size) of the amp is really up to you. The type of amp will depend upon the style of music and the amount of money you’re willing to spend. Most guitar amps have distortion, EQ, and other effects built-in to the amp. Some guitarists like to use the distortion of the guitar amp as well as a distortion pedal for instance. You should know how your amp sounds without all the effects turned on. See how clean you can make the amp sound without any effects plugged in. Then try turning up the distortion, if the amp has any, and hearing what it sounds like. This will enable you to have a better idea on how your guitar will sound when you start adding effect pedals and boxes. Another great test to hear how much different your guitar amp makes do this: ran your guitar through a reverb and then plugged the reverb’s output in to a guitar amp. Slowly turn up the distortion on the guitar amp. You should hear the difference between a clean guitar amp and a distorted guitar amp. This has the same affect as running the output of the reverb in to a distortion box. It’s very much a different sound as opposed to running the distortion box into the reverb. Of course your guitar sound can further be modified in the studio by applying more effects to your but that is for another day.

Types of effects

Floor Pedals – are the most common form of guitar effects. They are like effect modules which allow you to move or reposition the effect to various places within the effects chain.

Guitar Floor Effects Processors – These types of effects contain a number of effects in a self contained box which sits on the floor or desk top. They contain similar effect ‘modules’ as the Floor pedals but are usually in the form of software. They are more complicated to use but offer a wide range of effect possibilities as well as automation via MIDI.

Guitar Effect Modifiers

This is probably the main focus of this page in that many guitarists are more interested in these types of effects. Guitar Effect Modifiers come in all sorts and types, from foot pedals and desktop boxes to 19 inch rack-mount effects.

Overdrive or Distortion seems to be the most sought after guitar effect and is very important in many styles and not just rock or metal. Scotty Moore who was Elvis Presley’s guitarist is one of the first to use distortion. He turned up the volume control on the amp beyond what was then the normal position. It gave the guitar a mildly overdriven sound. Depending upon your style and the amount of distortion you’ll want will determine what type of distortion pedal to get. Many guitarist use the combined sound of both their guitar amp and distortion pedal to give them their overall guitar tone.

If you are doing blues and rock then maybe an overdrive pedal is what you’re after. This pedal will boost your tone and beef it up before it gets to the amp. It’s not really meant for adding massive amounts of distortion to your guitar but rather for giving it an extra boost while soloing or to dirty up a rhythm track. The overdrive pedal is really overdriving your guitar amp’s input.

If you are doing Metal then you probably want to use a distortion pedal. Something like the Boss MT-2 Metal Zone is more of what you are looking for. This is a more intense overdriven sound as that heard by bands like korn. Many metal guitarists remove much of the middle from their sound using an EQ. No matter what your taste and style in music is you may need to try out a number of different effect boxes before you find one that works for you.

EQ – Graphic and Parametric

Equalization can really change the tone of your guitar sound immensely. It can also be used to remove feedback that usually appears when playing through a highly distorted and loud guitar rig. There are two basic types of EQs that can be used with the electric guitar and in conjunction with your guitar amp’s EQ and they are Graphic and Parametric.

The Graphic EQ is more common than the parametric. It is used to remove or boost frequencies by sliding the various bands up or down. For metal players the graphic controls are usually move to form what looks like a ‘U’. This setting scoops out the middle giving you a more metal sound guitar tone. The graphic EQ can also be used to remove unwanted frequencies or frequencies that maybe feeding back. The graphic EQ can also be used to boost your guitar signal by adding or boosting the various frequencies. Some important tips on choosing a graphic EQ for your setup is the more bands the more noise. Don’t get a 31-band EQ if you don’t really need all 31 bands. Also many of the cheaper graphic EQs can deaden your sound and make it much less punchy.

The Parametric EQ is a better choice for those who want more control over their tone. It’s not as easy to use as the graphic but is more precise and accurate on removing tones and frequencies. They are also, usually, less noisy and have far fewer channels. Technically speaking the parametric uses three different parameters which are in the form of control knobs, but on many guitar parametric one of the parameters is fixed and there isn’t knob for it.

For each band you have to select the frequency and then either turn it up or down in volume. For feedback you would select the frequency you think is feeding back and then turn down the volume. If you’re not certain as to which frequency it is then turn the frequency knob until you hear the feedback diminish.

Dynamic Processors – Compressor Limiter

Though the Compressor is in the Dynamic’s family it is not the same thing as a Limiter. Technically speaking the compressor is used to decrease the dynamic range of a signal. This is used in radio and broadcasting so the audio level remains even. So signals after running through a compressor, will end up with their loudest and softest points closer together which is the same thing as saying less dynamic range. When most guitarists talk about compressors they are talking about more about attack and sustain than dynamics per se. To the guitarist the compressor, or sustainer as it’s also called, is used to increase the length of time the guitar string sustains. Most compressors made for the guitar re-label the ‘Release’ control to ‘Sustain’. Longer sustain settings produce a less choppy, or more smooth, sound while reducing it give a more balanced sound. The Attack setting also effects how fast the compressor acts upon the signal. A short attack means it will come on sooner while a longer time setting will produce a more even balanced sound.

Noise Reduction

There are two basic forms of Noise Reduction: Dynamic Filtering and the Noise Gate. Most guitarists are familiar with the noise gate. It will cut off the signal when it gets below a certain volume. So what happens is when you stop playing and the volume of your guitar gets below a certain level the noise gate turns off the sound. The volume level is set when you aren’t playing anything and is usually placed before the distortion box. It doesn’t filter out only noise it acts more as a valve which turns on and off the signal, even if the signal has plenty of 60 cycle hum and fluorescent light noise.

Dynamic Filtering is another way of actually reducing the amount of noise in a signal. It’s usually placed after the distortion box. It accomplishes noise reduction by analyzing the guitar signal for the top most frequency component present and then applies a high pass filter to remove the extraneous ‘noise’. Some units like the Rocktron Hush Super C also incorporate a ‘downward expander’ which is similar to a noise gate but better. The downward expander will lower the volume (gain) of a signal more when it goes below a certain level. When you are playing your guitar the downward expander doesn’t do anything, it keeps the input level and the output levels the same. When the signal gets below a level you select the rate upon which the signal is lowered (less gain) it more. You end up with quiet parts become quieter while normal guitar playing levels remain untouched. Many people love this effect while others say it changes their tone too much.

Modulation Effects – Chorus, Phaser, Flanger, Tremolo

These types of effects modulate the audio signal by slowly varying the pitch of the sound.

The Chorus is a one form of modulation that adds depths to your sound by simulating or doubling the sound of your guitar. It can be used on distorted signals but sounds really great when playing rhythm through a clean amp.

The Phaser produces a sweeping type of sound that is reminiscent of the 70’s. Some guitarist will use a very slow sweep that slowly changes the tone of the guitar over time. Turning up the rate gives you an under water type of sound.

The Flanger is really a very intense sound chorus effect and is accomplished by adding together a delayed version of the same signal. The amount of delay is changed which gives a more intense sweeping sound. The actual tonality of the guitar can get smeared and even lost if the flanger is set to intense.

The Tremolo is an effect that was found in amps from the early 50’s. It modulates or changes the volume up and down. These effects usually have a rate, and depth knob. Where the depth knob controls how far down in volume the tremolo will act. This effect was also made famous by the Fender Rhodes.

The Vibrato is similar to that of what an operatic singer is trained to do, vibrato. Vibrato slowly changes the pitch of the sound up and down. For guitar it’s a bit more complicated than this and sounds similar to a rotary speaker. Hendrix used one as did Robin Trower and many other guitarists.

Digital Delay and Reverb

Both of these effects can add another dimension to your guitar sound. They do this by mimicking an acoustical space through the use of delay. Most reverbs are a complicated matrix of short delays that create acoustical space.

The Digital Delay is cleaner sounding than the old analog delays that use bucket-brigade building blocks. Vintage digital delays are simulated by placing a low pass filter in the feedback loop. This filter simulates how an analog delay sounds with the high end of the guitar signal fading away with the delay. Digital delays can also be used to a slap-back 50’s sound to delays that are so long (2 or more seconds) you can build up harmonies by playing along with the delayed guitar part. Some guitarist who are known for their great guitar abilities are Brain May, Steve Via, The Edge, and David Gilmore. A good guitar digital delay is the Boss DD-6 Digital Delay

Digital Reverb is a great effect for creating a sense of space. The types of reverb units can be found in both rack and pedal formats as well as in desk top effect processors. The spring reverb is probably the first type of reverb available for the guitar other than recording in an actual reverberant room. Spring reverbs where first found in the early Fender, Gibson, and Vox amps, and are still very much used today. Running a reverb in to a distorted guitar amp will give you a very different sound as opposed to that of applying reverb to a distorted guitar amp sound. Many guitarists today will have reverb applied to the sound of their amp by miking it and sending it to the sound system. There are others who don’t use a guitar amp per se but rather a clean sound system and run their guitar effects, reverb and all, through this clean system. Digital reverb is one of those things that can easily make your guitar sound bad if you have it in the wrong location in your effect chain (See below for more info on guitar effects chain). A good guitar reverb is the Boss RV-5 Digital Reverb Pedal.

Harmonizers and Octavers

Octave pedal effects add an octave about or below that of the original guitar sound. They give your guitar a fattening 12 string effect like sound but are mostly used for signal note lead guitar playing. Jimi Hendrix was one of the first to make the effect popular when Roger Mayer made him the Octavia octave pedal.

The static Harmonizer is similar in effect to that of the Octaver but allows you to select different notes or intervals and not limited to just octaves. These are also called pitch shifters in that the shifted interval remains unchanged. Some Harmonizers allow you to add more than one harmony to the input signal. Most of these static types of Harmonizers are being replaced with the newer ‘intelligent’ one, but nothing really beats a simple harmonizer pedal. There are some guitarist who use the Harmonizer to add harmonics to their sound rather than a new note (fundamental). Sometimes odd intervals, ones that you wouldn’t really even think about using, are used. For example they would add 2 nd or minor 3, or even a dimished 4 th. The level at which these harmonies are added is somewhat low just enough to give the tone some depth and color. The only catch with this is I’ve noticed the guitarists where using a very expensive harmonizer (Eventide H8000).

Intelligent Harmonizers

Though Brian May of Queen actually played all the part to get his fantastic sound it can be simulated by using what is called an intelligent harmonizer. This harmonizer allows you to not only select the number of harmonies you want to add but also what key the harmonies will be generated in. Some even allow you to change the key from which the harmonies are generated in real-time. As mentioned previously the static type harmonizers use a constant pitch shift that doesn’t change when you change the note you are playing. With intelligent harmonizers you make sure your guitar is in tune with the harmonizer, then select the key you are playing in, like C Major, D minor etc… and the intelligent harmonizer does the rest. It will track the guitar notes and only produce harmonies that fit in that key. You can also get these for Voice (See Vocal Processors).

One of the more popular Octaver pedals is the Boss Octave OC-3 and a popular yet very expensive Harmonizer is the Eventide H8000 UltraHarmonizer.

Guitar Multi-Effect Processors

Guitar multi-effect processors have become more popular in recent years. The advantages are they are compact, contain a large number of effects, and can switch between completely different effect setups instantaneously. The disadvantages are they can sometime be more difficult to create or edit your effects. This is mainly because you can get lost in all the details of the processor itself and forget you are a guitarist. The other disadvantage is that on some guitar multi-effect processors only a small menu window is available. This makes viewing the whole guitar preset very difficult to do. These disadvantages usually subside once you get the hang of how the system works.

Basically the guitarist will create or use one of the many built-in effect presets. These presets contain a number of effects in a particular sequence and setup using unique sound parameters. For instance an Acoustic Guitar type preset may contain an ‘Acoustic Guitar’ emulator effect followed by a Chorus and finally a short digital delay effect. A distorted guitar preset may contain a compressor, distortion, EQ, and digital delay. The guitarist can then simply switch between these two effects.

If you remember that adding another pedal type effect to your effects chain increases the amount of noise of the guitar sound. Since the multi-effect processor is full of different effects it allows you to add only those effects you are going to use in the preset. If you did this in the guitar pedal world you have to have a large number of different pedals plugged in and ready to play. This however just isn’t very practical. Switching between two completely different effect types simultaneously can prove to be a challenge as well. The multi-effects processor solves these two problems by allowing the guitar to select from a number of effects to create a ‘Preset’. These presets are stored in the multi-effects processor where they can be called up at anytime. Each preset can contain a number of effects like compression, distortion, pitch shift, delay, chorus and the like. The effects can also be switched between at a moments notice. They can also be inserted into different points in the effects chain as well. Multi-effect processors also include all the effects previously mentioned in this article. Some of the effect include: Dynamics, Modulation, Harmonization, Reverb, Noise Reduction, Wah, Delay and other effects. Some of the more popular Guitar multi-effect processors are the Line 6 PODXT Live and the Boss GT-8

Guitar Amp Modelers

Guitar amp modelers and multi-effect processors are very similar in that if the multi-effects processor has distortion it’s probably using guitar amp modeling algorithms. There are some multi-effect processors that don’t included guitar amp modeling. With these units a guitar ‘pre-amp’ is usually used prior to the multi-effects unit. Today you’ll find most Amp modelers are built-in to guitar based multi-effect processors. One of the main advantages of using a guitar amp modeler is variety of sound and lower cost.

These types of effects are created by first listening to how an amplifier responses when presented with a know signal and then creating a mathematical formula based upon the data collected when modeling the amp in question. Sometime a simple sin tone is plugged into an expensive tube based amp, say a Mesa Boogie Dual Rectifier. The output of the amp is then compared to the original signal and the changes are noted. This type of analysis goes on until enough data is present to create an accurate model of the amp. With a number of reference points you can build a fairly accurate amp model. Not only have guitar amps been modeled but other guitar effects as well as microphones, mic preamps, speaker cabinets and many other devices. Many guitar tone purist don’t like this type of thing as they feel it’s cheating in some way. These types of amps are probably the most popular because younger guitarist, or their parents rather, can afford them as well as save their hearing because the necessarily have to turn it up to 10 in order to get ‘that sound’. Some of the more popular guitar amp modelers are from Line 6 and DigiTech as well as the Marshal JMP-1. Line 6 also has a number of guitar effect modelers available as well.

The Effects Chain

The effects chain is really a sequence of effects where one effect is followed by another effect. The last effect in the effect chain is the most predominant. This is only one possibility on arranging your guitar effect chain. These become quite elaborate and complicated using a number of different means (switches and routers).

This particular chain of effects is too long and will produce a lot of noise but is here so you can get an idea on where some of the effects could be placed. One special effect is one many guitarist forget about and that’s the noise gate. The noise gate can be very useful for eliminating the accumulated noise produced by each effect. Some place the noise gate at various places in the effect chain but usually before the distortion and compressor. But interesting effects can be made by breaking the ‘rules’.

Guitar->Wah->Volume->NoiseGate->Compressor->Distortion->EQ->Chorus->Delay->Reverb

Note: The Volume pedal is before the Distortion module. This will sound different than having the volume pedal after the distortion. Here when the volume pedal is turned up more distortion is applied to the signal. When the volume pedal is after the distortion the amount of distortion remains the same only its volume changes.

Your guitar’s sound will be better using fewer effects. Use only the effects you really need in your chain. Many guitarists effect chain is somewhat smaller than that listed here.