Although the main defining characteristic among amplifiers is whether they are tube or digital (a topic you can read about here in part one of this series), there are a wide variety of other factors to consider as well when purchasing an amp. In part two of this guide to amplifiers, we are going to go over what the main different specs mean and what variables might be right for you. It’s worth noting that there are many specs that we won’t go into in this piece, but that’s because most of the little specs mentioned are pretty inconsequential. Most guitar amps will mention what input they take, but you’d be hard pressed to find one other than a ¼” cable, and it won’t make a difference in your tone whether your amp’s outer layer is vinyl or tweed. 

Cabinets vs. Combos

Any amp on the market is going to either be a cabinet or a combo. A simple but important distinction, a cabinet amp is one where the speaker and the controls are sold separately while on a combo amp they come built together as a single unit. An amp cabinet allows you to mix and match combinations, thus giving you more control over your tone and often more raw power to work with. However, as both necessary parts are sold separately, buying an amp cabinet will often cost significantly more than a comparable combo amp, an element that is only magnified by the fact that most cabinets currently on the market are on the high-end of things as is. 

While combo amps lack the flexibility of creating your own cabinet, they have the advantage of being a fully functional unit in and of themselves. This means that if you buy a combo amp, it is the only purchase you’ll need to make in order to start playing right then and there (assuming that you have something to plug into it). Additionally, combo amps tend to run for far less money than amp cabinets and much more convenient to travel with.     

Wattage

A watt is a unit of measurement that quantifies power and has wide usage outside of musical equipment. Within the world of guitar amps, wattage refers to the amount of electric power that drives an amplifier’s speaker. Simply put, higher wattage means a louder maximum volume. However, it’s worth noting that tube amps can achieve significantly more power than digital amps with the same amount of electricity, and a result will have a much lower wattage than a digital amp with a comparable output. 

Although these exact parameters are a bit subjective, generally a tube amplifier up to 20 watts or a digital amplifier up to about 30 watts can be considered low wattage, a tube amplifier of about 20 to 40 watts or a digital amplifier of 30 to 100 watts can be considered medium wattage, and a tube amplifier of 40 to 100 watts or a digital amplifier of 100 to 200 watts can be considered high wattage. Although there are both tube and digital amplifiers on the market that exceed these parameters, that amount of wattage is generally unnecessary unless you’re playing to arenas.  

By reading what’s written above, you may be thinking to yourself that you’d want an amp with a high wattage, and you may not necessarily be wrong. However, there is more to consider than simply high wattage versus low wattage. For starters, amps with high wattage are almost always going to be larger and will usually be more expensive. This means that when looking at wattage, the main thing to consider is what it is that you will be using this amp for. 

If you’re looking for an amp to use in a live setting, particularly within the context of something along the lines of a loud rock band where volume is important, then a high wattage amp is probably what you’re looking for. However, if you are looking for a bedroom, practice, or recording amp where the ability to achieve high volumes isn’t particularly important, then it may make sense to get an amp with lower wattage. As higher wattage amps tend to be more expensive, you can often get an all-around nicer amp with lower wattage for around the same price as a higher wattage amp that doesn’t quite stack up in other ways. Additionally, as higher-wattage amps are often physically larger, lower wattage amps tend to be more convenient for such things as storage and travel. 

Controls

One of the more self-explanatory specs we’ll be going over, controls refer to what elements of the amp’s tone can be controlled with knobs. When looking over an amplifier’s spec sheet, the controls section will generally consist of a simple list of the knob’s labels. A typical one of these lists may look like the following: Volume, Gain, Bass, Middle, Treble, Reverb. This would mean that those are knobs that could be found on this hypothetical amplifier, and thus the elements of its sound that you would be able to fiddle with. 

When looking at an amp’s controls, it is perhaps more important which controls are missing rather than which ones are present. For example, if an amp does not have reverb listed as a control, then it’s probably safe to assume that that amp does have reverb capabilities, so make sure that an amp has a control for every element you’re hoping for it to have. 

Effects

While this is a bit too broad of a topic to fully do justice here, it’s worth noting some amplifiers will come with built-in effects of the sort that one can get from a pedal. Although many tube amps come with built-in analog reverb and natural overdrive effects, and some come with a built-in tremolo effect, for the most part, built-in effects are associated with digital amps. Most digital amps will have some degree of built-in digital overdrive/distortion, and some have built-in versions of less common effects, such as delay and modulators. An amp with built-in effects can be a great way to have fun and experiment with new sounds, but the sounds of built-in amps effects typically won’t stack up in terms of quality to those found in a pedal, and built-in amp effects are very rarely used among professionals. 

Speakers

The final element that we are going to talk about is also one of the most important. A guitar amp’s speakers are exactly what they sound like, and I don’t think that we really need to spend time getting into what a speaker is. However, something that is less commonly known is that smaller amplifier speakers produce tones with more clarity in their treble frequencies, and larger amplifier speakers produce tones with more clarity in their bass frequencies. 10” speakers will provide sharp, treble-leaning tones while still being large to create volume required by most live music situations, while 15” are the standard size speakers for players interested in bassier tones. 12” speakers make for a happy medium between the two, and are the most common-size speakers among amps currently on the market. Smaller sized speakers (specifically 6” and 8” speakers) can also be found, but they typically aren’t powerful enough for live situations where one may have to compete with other instruments.