Tube or solid-state? What’s the difference between them anyway? It’s important that you do your homework when trying to find the right guitar amp for your needs. That’s why you’re here, isn’t it? Read on for an exhaustive guide on tube guitar amp vs solid-state guitar amps.
Tube amps, or valve amps as they’re also known, are a class of amplifier that use vacuum tubes to amplify a signal. A vacuum tube is a glass tube that holds electrodes (special electrical conductors) inside an evacuated chamber. Vacuum tubes were developed in the early 20th century, originally for audio and communication setups. However, they proved just as effective in other applications, leading to the rise of guitar tube amps.
A typical tube amp has 2 stages of amplification — pre-amp and power — with each stage employing its own set of tubes. Pre-amp tubes are tasked with boosting and shaping the raw incoming signal. Power tubes drive it the rest of the way, amplifying the signal up to speaker levels. It’s common for effects and reverb modules to be placed in between pre-amp and power tubes.
Tube amps are a hundred percent analogue in operation. They’re also quite the fragile species (as is anything else with glass components). More on that later, but you’ll find that tube amps function differently depending on how you treat them. Keep things civil and the amp yields a crisp, clean signal as you might expect. But when you turn up the volume, things start going haywire (albeit pleasantly). Turning up the volume essentially overloads the tubes with power. This “breaks up” the output signal, creating what we now know as ‘overdrive.’ You will also note that tube amps respond to the intensity with which you strum your guitar. I love the tube sound.
While tube amps come in many different types, they fall into 2 broad categories based on how they operate. These include Class A and Class AB. Class A amps operate by pushing current through the tubes continuously even when there’s no signal; picture a car idling in neutral with the throttle pushed all the way down. Running this way gives Class A amps the ability to distort quicker when you increase the volume.
By contrast, Class AB amps split their operation across a couple of tubes to separate the positive and negative voltages. This allows them maintain the same ‘always on’ state as their counterparts, albeit without consuming as much power. Class AB amps are preferred in instances that require lots of headroom (the ability to run without distortion).
Solid-state amps work pretty much like valve amps: the input signal is amplified by sending it through a series of electrodes. Most have 2 stages of amplification as usual, with effects like reverb and EQ placed between them. Unlike their analog, however, solid-state amps don’t come with vacuum tubes; they employ transistors instead.
So why the name ‘solid-state’? The term derives from the fact that transistors use semiconductor technology instead of electron tubes. This means they don’t burn out as often — hence are solid in their state. Other than that, solid state circuitry allows for miniaturization (reducing something in size without losing functionality). In essence, any given solid-state amp will have a much smaller footprint than a comparable valve amp.
Solid-state amps also tend to be less-delicate in operation. Basically, they allow you to turn up the volume without worrying about ‘over-saturation.’ A solid-state amp will still distort when you crank it up too high, make no mistake. However, the distortion ceiling is way higher with solid-state technology than what you’d get from a valve amp.
This lack of sensitivity can also present a drawback, obviously. A solid-state amp doesn’t really give you room to influence the tone. This is largely due to how transistors work — you can only switch them ON/OFF. As such, varying your style of play won’t produce much of a difference in the output sound. The binary mode of operation also means that solid-state amps don’t distort cleanly.
Comparing Tube Amps and Solid-State Amps
You now have a good picture of the inner workings of both kinds of amplifier. Let’s look at the key differences between them:
- Mechanism: Tube amps are based on vacuum tubes , while solid-state amps employ transistors. Vacuum tubes consume lots of energy in operation; a tube amp will always consume more power than its similarly-rated solid-state counterpart.
- Tone: Tube amps have a warm, natural sound that distorts linearly as the volume is raised. Solid-state amps tend to yield a bland sound in comparison. While recent models have narrowed the tonal gap somehow, they can never quite catch up in that regard.
- Response: A tube amp allows you to fine-tune the output as you see fit — the same of which cannot be said of their counterparts. But this flexibility comes at a price. Tube amps need warming up before being kicked into life. Solid state amps, on the other hand, are always ready for action on a moment’s notice.
- Versatility: While tube amps are versatile in operation, solid-states tend to be more adaptable in the real world. Manufacturers take advantage of the available circuitry to incorporate a host of effects, and this translates to more flexibility on the stage.
- Maintenance: Neither amp requires much in maintenance, strictly speaking. But as you might have guessed, valve amps can be a little demanding here. Vacuum tubes have a life expectancy of 1-2 years, at which point they need replacing. By contrast, a solid state amp could last a decade with all its original components. Tube amps also tend to be pricier as well.
So, What Now?
Here’s the thing: the kind of amplifiers to choose all comes down to what you want — and your wallet, of course. If you’re aching for that classic warm guitar tone with lots of oomph, go for a tube amp. But if you just want a decent sound — or perhaps don’t have the time for pesky maintenance — solid state is the way to go.