Getting to know the different guitar amp types can be difficult if you’re just getting started with guitar. I remember when I first started looking for a guitar amp over 15 years ago – I had no clue what I needed!
So I’ve written this complete guide to give you an overview on the different types of guitar amps, what they’re good for and some general pro’s and con’s based on my real life experiences.
Here’s the main thing to take away:
There are four basic guitar amp types: tube amps (sometimes called valve amps), solid-state amps, modelling amps, and hybrid amps. Tube amps are known for their vintage sound. Solid-state amps are used for modern styles of playing. Hybrid amps are a blend of both. Modelling (or “digital”) amps are basically computers that simulate other amps.
You can also either get a “combo amp” which is an amp with a built in speaker, or an “amp head” that processes the sound but will need a speaker connected to make a sound.
Now, let’s take a deeper look.
Tube amplifiers
Tube amplifiers (also called “valve” amplifiers in the UK) are the granddaddy of guitar amps. They’re coveted by many guitarists because of their rich, warm tones and have been used by countless guitar legends over the years.
This type of amp gets its name from the vacuum tubes it uses to process your guitar’s signal. A vacuum tube is a small, glass cylinder that looks a bit like a lightbulb. It contains many different components that increase, or decrease, the amplitude of your guitar’s signal.
Pretty much any guitar amp made before the 1960s used valves, which is one of the reasons they’re so revered by the guitar community – especially those looking for that vintage rock and blues sound.
How tube amplifiers work
Most tube amplifiers use vacuum tubes in both the preamp and power amp sections. The preamp section increased your guitar’s signal to line level, and is used to shape the tone and EQ of your guitar’s sound. The power amp section handles the amps overall volume.
When you increase the level of the signal going into the preamp, the vacuum tubes create a very warm sounding distortion. This sound is the reason that so many people love these amps. The overdrive from a tube amp sounds very natural compared to more modern designed amps.
My theory is that it sounds better because it sounds familiar. Remember, tube amps have been used since the electric guitar was created. They developed hand-in-hand together. So, the classic electric guitar sound is, in part, the sound of a tube amplifier.
Advantages of tube amps
As I’ve said, tube amps are considered the holy grail of guitar amps by a lot of people. Let’s take a look at a few reasons why people love them so much.
- Tone: Valve amps have a crisp, unique tone that you can’t really get from other amp types. Most guitarists swear by their valve amps and wouldn’t touch any other kind of amp with a ten-foot pole.
- Output: Valve amps deliver more output per watt. We’ll discuss watts later, but a valve amp will generally be louder than a solid-state amp with the same watt rating.
- Maintenance cost: They are usually cheap to maintain. Because valve amps don’t have any complex components, it’s cheap to replace most components, and you can even replace them yourself (if you know what you’re doing!).
Disadvantages of tube amps
Despite what some people might think, these amps aren’t perfect. Let’s look at some of the downsides to tube amps.
- Expensive: Valve amps are more expensive. They’re usually the most expensive amps you can buy, mainly because vacuum tubes are so specialized these days.
- Maintenance requirements: Depending on how often you use your amp and how high you push the volume, you’ll have to replace the tubes eventually. Sometimes it’s as much as once a year, but it could also be as little as once every ten years. It all depends on the amp’s build quality and how often (and loudly) you play.
- They’re loud: Everyone wants a loud amp – except your neighbours. To get the best sound of a tube amp, you have to crank up the volume. For practice and home use, this can be a bit too loud. Devices like attenuators exist, that scale the volume down while preserving the tone, but this costs additional money.
My opinion: I think valve amps are great. I used to own a Vox AC15C2, and it sounded amazing. When the volume was turned up, it had the most amazing overdriven tone. It was both warm and bright. Mellow, but cut through a mix. And, playing live, this thing was loud.
But, I found that it was just way too loud for home use. I could have bought an attenuator – but I didn’t know about them back then!
I’d recommend a valve amp to any guitarist looking for an amp that has a lot of warmth and character.
Solid-state amplifiers (transistor amps)
Solid-state amps do essentially the same thing as tube amps. They also have preamp and power amp sections. The preamp section deals with the tone and EQ, with a bit of amplification, while the power amp section boosts the volume.
The difference between tube amps and solid-state amps isn’t what they do but how they do it.
How solid-state amplifiers work
Solid-state amps don’t use tubes. Like most other electronics, tubes were largely replaced in the 1960s and 1970s by more efficient surface mounted devices (SMD’s). SMD’s are essentially really, really small electrical components.
But, these devices don’t create the same kind of harmonic distortion that tubes do.
A lot of people believed that solid-state amps would take over from tube amps entirely, since that is what happened in all other industries. But, that wasn’t the case.
Some guitarists feel that solid-state amps sound colder and more brittle compared to the warm and inviting tones of a tube amp. This was a lot truer in the early days of these amps. But, over the year, the kinks have been worked out, and the tonal gap between the two amps have been closed in a lot of places. In my experience, it’s the cheaper solid-state amps that tend to sound cold and shrill.
Unfortunately, a lot of the culture surrounding guitar playing is based on legacy. So, solid-state amps still tend to be shunned by a lot of guitarists. But, solid-state amps have been, and continue to be, used by many guitar legends.
Advantages of solid-state amplifiers
There are some advantages to solid-state amplifiers:
- Price: Solid-state amps cost less than valve amps. This makes them ideal for beginner guitarists who haven’t decided how serious they are about their guitar-playing yet, since they are less of an upfront financial commitment.
- Durable: Solid-state amps can theoretically last longer with less maintenance. Apart from replacing the occasional fuse, solid-state amps could last you a lifetime. SMD’s have a longer lifetime than vacuum tubes by their very nature.
- Weight: These amps are lighter. Solid-state amps often weigh a fraction of a similar valve amp, making them easier to carry to gigs and move around on stage.
Disadvantages of solid-state amplifiers
- Sound: Cheaper solid-state amps can have lower-quality sound. As mentioned, the tonal variance and harmonic distortion added by the vacuum tubes can’t be matched by solid-state amps. The gap has closed over the years, but is still noticeable in cheaper solid-state amps.
- Resell value: Solid-state amps have a lower resell value. Because they are not as popular, you can’t sell a second-hand solid-state amp for nearly the same price as a second-hand valve amp.
- Repairing: While SMD’s are great for saving space, they’re notoriously hard to fix. This is because they’re usually very small, and bunched close together. Fixing a solid-state amplifier usually requires specialist attention, which can get expensive.
My opinion: The myth that solid-state amps are cold and tinny sounding used to have some merit, but the tonal gap between tube amps and solid-state amps has closed a lot over the last decade.
These are affordable, durable amps that are great for those of us on a budget and looking for something that will last. I recommend not going for the cheapest available option though, as they can sound a bit thin.
Hybrid amplifiers
A hybrid amp combines the pros and cons of valve amps and solid-state amps into one unit. Usually, the preamp section will have tubes to create the unique tone of tube amps, but then the power amp section will use transistors, like other solid-state amps.
This is an excellent compromise since you get the tonal warmth of a tube amp but at a much lower price and requiring less maintenance.
My opinion: I currently use a hybrid amplifier, the Vox VT15. It’s got a great tube tone with a small profile, and is a great amp for home practice, and for beginners!
I’ve played on more expensive hybrid amps, and they’re very close to the sound of full tube amps, at a fraction of the cost. If you’re on a budget, but want that vintage tone – check out a hybrid amp!
Modelling amplifiers
Modelling amps are essentially computers that simulate amps. They are the next step in the evolution of solid-state amps since processors are essentially chips that emulate different circuitry.
In principle, modelling amps are solid-state amps with built-in signal processing. This enables them to simulate the effects created by famous types of amps. A modelling amp is a way to go if you want a quick and cheap way to “sound like” a particular guitarist.
Most modelling amps allow you to dynamically change settings and presets to sound different instantly. You can get a very similar same tonal variance and harmonic distortion that you can get from valve amps.
Like anything else that isn’t a tube amp: modelling amps are usually looked down upon by vintage tone seekers, seeing them as a sub-par imitation. And to some extent, that’s a fair statement. But, for a lot of us, these amps provide a very affordable way to access a lot of varied amp sounds – without needing a studio.
Some famous and legendary guitarists use modelling amps or other forms of amp simulation. They include Lemmy (Motörhead), Malcolm Young (AC/DC), and the Grateful Dead’s Bob Weir.
Digital Modelling Amps (VSTs)
Some modelling amps don’t look like traditional amplifiers. Modelling amps like the Neural DSP quad-cortex and Line 6 Helix LT look more like fancy effects pedals than traditional amps – but they work just the same.
These are essentially VST’s (Virtual Studio Technology) that use computer code to emulate amps. They can come as pieces of hardware, or software that you can install on your computer – like Guitar Rig and AmpliTube. Using a VST could save you hundreds of dollars and potentially thousands in the long run – though they can be pricey themselves!
My opinion: I use modelling amps and VST’s all the time. For me, they are so much easier to use for recording than a normal amp. Not only that but they sound great. I don’t have any stats to back it up, but I’m confident that most people wouldn’t be able to tell the difference between a modelled amp and a real one.
That being said, some software can require a lot of processing power to run, so you might need to upgrade your computer to use them (in which case, you might as well buy an amp!).
For me, they’re great because they just work. I don’t think they completely replace the need for an amplifier (yet!), but they’re a great tool for any guitarist to have and to learn.
Combo amplifiers
When most people think of a guitar amp, they’re thinking of a combo amplifier. These are amps where the amp head and the speaker are combined into a single unit. This design is done for simplicity, so that guitarists don’t have to assemble and build their own amps.
But, there are amplifiers available without the speakers – these are called “amp heads”.
What is an amp head?
An amp head is the part of an amplifier that receives the input signal from the guitar, passes it through the preamp and power amp components (valve or solid-state), and finally sends it to an output. If you removed the speaker from a combo amp, you’d have yourself an amp head.
As amp heads can’t produce a sound by themselves, they need to be connected to a speaker – usually in the form of an amp cabinet.
What is an amp cabinet?
An amp cabinet (sometimes called a “stack”) is a speaker or set of speakers contained inside a box shaped frame. You can select an amp head and a separate amp stack that you can combine to achieve the perfect amount (and type) of output. Having the amp head and amp cabinet as individual units allows you to mix and match components and brands to get the best possible results.
This type of setup is usually used by professionals and recording studios. Beginners are probably better off using a combo amp, until the time comes to upgrade!
What do Watts mean on an amp?
Watts are the amount of power a device or appliance can produce or handle effectively. In a guitar amp, the watts don’t mean volume but rather the amount of volume that it can handle without breaking up the sound. In other words, the watt rating on an amp doesn’t indicate how loud it will go – but rather how far you can push it.
It’s important to note that tube amps generally tend to perform better with lower watt ratings than solid-state amps. Most guitarists find that a well-built 5-watt tube amp can handle the same volume levels as a 15-watt solid-state amp.
Conclusion
Now you know the differences between the guitar amp types, and it should be easier for you to decide which one you prefer. Tube amps have the vintage sound, but come with a high price tag. Solid-state amps are best for beginners, but can sound a little cold if it’s a cheaper model.
For a beginner, a modelling combo amp is the best choice as it provides a compact single unit that’s great for practice and will give you a wide range of sounds.
But, always remember that guitarists tend to be opinionated – but their opinions don’t matter. The best thing you can do is to head to your local guitar store and play around with different amps to hear which ones you prefer.
Conor is a music producer, multi-instrumentalist, and all-round enthusiast from the UK with over 15 years of experience. He’s the founder and sole-content creator for the roundtable audio blog and YouTube channel.
