Examining the Different Parts of a Guitar Amp
The main purpose of an electric guitar amplifier is to make the source signal from your guitar loud enough for an entire room (or even an entire stadium) to hear. But modern guitar amps can do a great deal more. Read on for an overview of the component parts of a guitar amp and how they can function together to produce your desired sound.
Basic Components of a Guitar Amp
A guitar amp consists of two essential parts: the preamp and the power amp to perform its core amplification function.
Preamp Section
The preamp section of a guitar amp modulates the weak auditory signal from an electric guitar, both boosting it and shaping its sound. Signal boosting is technically necessary to send a line-level signal for further amplification, but guitarists tend to be most interested in the power amp's sound-shaping capabilities, which can add sonic qualities such as distortion, brightness, saturation, and color.
Power Amp Section
While the preamp gives your signal some muscle, the power amp does most of the heavy lifting when it comes to amplification. It dramatically increases the volume of your sound as it sends a final signal through an output channel (most commonly, a built-in or connected speaker). Most guitar amps house a preamp and a power amp within a single unit.
Tone Control Features
Although they vary in complexity, guitar amps generally have at least some basic tone controls that allow you to adjust the sound to fit your playing style and the demands of the situation.
EQ Controls
The preamp gives your guitar amplifier its core sound by supporting various equalization (or “EQ”) controls. EQ controls may be quite complex, or they may take the form of three simple knobs: a bass knob (to increase or decrease the volume of low frequencies), a mid-range knob (to increase or decrease the volume of mid-range frequencies), and a treble knob (to increase or decrease the volume of high frequencies).
Presence and Resonance Controls
Beyond simple EQ, some guitar amps allow players to adjust the tone with presence and resonance controls. Altering frequencies often beyond the high range of standard treble controls, presence controls can make your guitar sound brighter and more cutting, without coming across as overly harsh. Resonance controls operate similarly but target low frequencies rather than high ones. They can make your guitar heavier and emphasize growling and thumping sounds.
Effects and Modulation
In addition to tone controls, most amps have some sort of reverb function that mimics the effect of soundwaves reverberating off physical surfaces like walls, ceilings, and floors. But reverb is only the beginning of the sound effects that a guitar amp can produce.
Built-in Effects
Many guitarists turn to separate effects pedals or boards for the sound modulation and effects they want. However, you can also get chorus, delay, overdrive, and additional guitar effects built directly into your amp. Some amps feature multiple channels that allow guitarists to switch easily from effect to effect.
Loop Effects
The effects loop of a guitar amp refers to any group of effect units or pedals that can be inserted in the signal flow after the preamp and before the power amp. This gives players greater control over signal chain order, helping them optimize their sound.
Speaker Components
A guitar amp does a great deal when it comes to processing the electronic signals that will ultimately become your guitar sound. But to actually produce sound, a guitar amp must be connected to a speaker.
Types of Speakers Used in Guitar Amps
Guitar amp speakers can be built directly into the amp (a configuration called a “combo unit”) or contained within a separate cabinet and connected with a cord. They can also be categorized according to size. Smaller speaker sizes (generally less than 10 inches in diameter) are best for music with clean tones played in a smaller room. Larger speaker sizes (generally over 15 inches in diameter) are best for making a large sonic impact in a larger venue or recording studio.
Speaker Cabinet Design
A cabinet is the box in which a speaker sits. Cabinets are designed to amplify bass tones, separate tones, and absorb soundwave and air pressure shocks.
Connectivity and Outputs
The inputs and outputs on your amp allow you to source and direct the signals that flow through it.
Input Jacks
Guitar amps generally come with one or more standard ¼-inch instrument cable input jacks. This is how you plug in your guitar.
Output Options
The primary standard output for a guitar amp is the speaker. But, depending on your amp, you may also be able to output your signal to a headphone jack for practice or another direct line to a soundboard, effects unit, mixer, or other piece of audio equipment.
Tips for Amp Care and Maintenance
Because amps can easily overheat, you should ensure that they receive proper ventilation and are kept free of dirt and debris. You should also know your amps limitations in terms of rough handling and maximum volume. And, of course, you must perform regular maintenance and repair on your amp to address failing components.
Visit Brian's Guitars for Quality Amps and Components
To learn more, check out our carefully curated collection of amplifiers at Brian's Guitars. We also have extensive electric guitar and guitar accessory collections to help you find a full setup that is right for you.