What Are Class A Guitar Amps

As you may already know, there are different guitar amp classes and all of them work slightly differently.

One of the most popular tube amp classes is Class A but you may not know what it means and how it sounds.

Class A guitar amps are a type of amplifier that uses a single-ended, single-pass configuration. This means that the signal is passed through a single amplifier stage, providing a warm, natural tone ideal for blues, jazz, and rockabilly music.

I’ll go in-depth and explain how it works and how it sounds, but before you read this, I recommend you understand what types of guitar amps exist.

How Class A Guitar Amps Work

diagram of class a guitar amp

As I have already said, Class A guitar amps work by using a single-ended configuration, which means that the signal is passed through a single amplifier stage.

For example, in contrast, Class B guitar amps use a push-pull configuration, where the signal is passed through two amplifier stages, providing a more powerful and distortion-filled tone that is ideal for heavy metal and rock music.

One of the key factors in the tone of a Class A guitar amp is the type of tubes used. Class A guitar amps typically use vacuum tubes, also known as valves, which are an essential part of the amp’s tone.

Vacuum tubes provide a warm, natural tone perfect for different genres of music. They also provide a distinctive compression and sustain that is not found in solid-state amps.

How Class A Guitar Amps Sound

class a amp preamp

Now that you know a bit about how Class A guitar amps work, let’s talk about how they sound.

Class A tube amps have a natural, organic sound with warmth and clarity and minimal crossover distortion.

Class A amps also have a high amount of negative feedback, reducing harmonic distortion and increasing efficiency.

However, this results in a less dynamic and touch-sensitive response compared to other amplifier classes.

Also, if you compare Class A to Class A/B amps, Class A will sound louder and could be great for big stages.

Famous Class A Tube Guitar Amps

There are many Class A guitar amps available and you can use this type of guitar amp in different genres.

One of the most popular Class A amps is Fender Blues Junior which is ideal for players who want a warm, natural tone for their blues, jazz, and rockabilly music.

Another Class A amp from Fender is Bassbreaker which is a great-sounding amplifier for blues players.

If you are interested in Class A metal amps, then you can try Bugera G5 Infinium, which is one of my favorites. It includes reverb, power attenuation, and morph EQ.

And another great example of a great Class A tube amp is the Supro 1969TH which is a unique-sounding guitar amp with awesome features and perfect for a vintage sound.


Class A guitar amps are a popular choice among guitar players regarding genre or playing style. They work by using a single-ended, single-pass configuration, which provides a warm, natural tone that is ideal for these genres.