How To Test an Amplifier: A Step-by-Step Guide for Beginners

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If you recently bought an electric guitar or are planning to, you need to get an amplifier.

This device can boost your guitar’s signals and make it sound better.

However, you should first know how to test an amplifier before heading out to a nearby store to buy one.

There are many options available in the market, and it is not easy to find the right guitar amp for you.

Knowing how to test it will help you avoid experiencing buyer’s remorse.

We got you covered with this guide, but let us first see how a guitar amp works. 

How Does a Guitar Amplifier Work?

It is possible to play your guitar without an amplifier, but you need it to play for a large group of people.

If there is a good chance of this happening, you should invest in an amplifier now.

That said, before you try learning how to test an amplifier, it is best to understand how it works.

How the Signal Is Made

Your guitar is built with a device known as the pickup.

It is responsible for converting the strings’ vibration into an electrical signal.

It consists of a copper wire wound around a permanent magnet, creating a magnetic field.

When you pluck a string, the resulting vibration disturbs this magnetic field, generating a small amount of current in the pickup.

This electrical signal gets sent to the amplifier, where it gets boosted to higher levels.

The Preamp Stage

Amplifiers typically have two stages: the pre-amplifier or preamp and the power amplifier.

The signal from the guitar first goes to the preamp, where it gets amplified to a certain level.

This process will help prepare the signal for the power stage.

It will also define the sound and the signal’s overall tone using bass, middle, and treble controls.

In some models of amplifiers, the preamp can even add overdrive to the tone, making it gritty or fuzzy.

The Power Amplifier Stage

Once the preamp is done processing the signal, it goes to the power amplifier.

As its name implies, the power amplifier boosts the signal several times.

In short, it controls the volume of the electrical signal.

The Speaker

After the power amplifier, the boosted signal goes to the speaker, where it gets converted back into sound.

This process is made possible by the speaker’s motor or voice coil that causes vibration on a diaphragm.

In turn, the diaphragm generates vibrations in the air surrounding it, creating the sound that you hear from the speaker.

tips on how to test an amplifier

How To Test an Amplifier

Amplifiers cost between hundreds to over a thousand dollars.

While this amount won’t sink your budget, you still need to get the most value for your money.   

That is why it is important to test the amp before you buy it to evaluate its sound and decide if it is best for you.

Check the Power Source

Before you plug the amp in, check that the socket is live and not controlled by a separate switch.

Turn the Volume Down

After checking the power source, make sure you turned the master volume control all the way down.

Turning the volume down will ensure that you do not make sudden loud noises once you turn on the amplifier.

It will prevent disturbing other shoppers or, worse, blowing a fuse in the speaker and damaging the amp.

Plug the Amp In

Plug the amplifier into the power source, then hook up your electric guitar to it.

Turn the Amp On

Flip the switch on and check that the LED indicator lights up.

Set the Controls

To get a neutral sound at the beginning, turn the bass, middle and treble knobs halfway to the max position.

Play Your Guitar

Once you set up everything, you can finally start playing your guitar.

Try out a few licks at first, using different tones and volumes.

You should do this on different parts of your guitar.

Listen closely for any distortions while you are doing it.

Watch Out for Buzzing

One of the things you need to look out for when testing an amplifier is the buzzing sound.

This happens when the preamp distortion becomes unrestricted, which compresses the sound.

You can also hear it sizzling when at high volumes.

To test for the buzzing sound, turn the master volume up and the gain down.

Next, adjust the amplifier to the output level you prefer to use, then slowly turn up the gain.

If the tone becomes buzzy while increasing the gain, you should look for another amplifier to test.

Things To Remember Before Testing an Amplifier

Before you head out to the music store to look at amplifiers, there are a few things that you need to keep in mind.

Bring Your Guitar

Remember to bring your guitar along with you.

Not all guitars are built the same, even those of the same make and model.

There will be subtle differences, and each one will impact which amplifier you should get.


Next, do some research first, so you have a general idea of what amplifier to get.

For instance, you should know what size amplifier you need based on the space in your apartment.

When you enter the shop knowing this, the store assistant won’t be able to pressure you into buying anything bigger.

That said, keep an open mind when it comes to choosing what type of amplifier to get.

If you are a big tube amp fan, you can take this opportunity to try out digital or solid-state amps.

You might surprise yourself and find other amplifiers more appealing this time.

Amp Speaker Size

Finally, pay attention to the size of the amp’s speaker in the same way you do its wattage.

The amp’s tonal attributes vary with speaker size and could affect your decision-making process.


Aside from the instrument itself, the amplifier has the most significant impact on your guitar-playing experience.

You must weigh all your options carefully before deciding, so you end up with the best possible option.

Hopefully, this guide will help you choose the best amp for you.