One question I am often asked is: “What kind of amp should I buy?” When it comes to amps there are lots of variables, but the most important thing to consider is whether you will buy a tube-amp or a solid-state amp. Before we get into this, let’s break down how your amp works. There are three basic stages involved in amplifying the sound that comes from your guitar.
First, there is the input stage, which is called the preamp. The preamp takes your signal from your guitar, via your instrument cable, and “colors” it with various controls: eq (equalization), gain, reverb, etc. This signal is then passed on to your power amp, which amplifies the signal and sends it to your speaker, which then turns the electrical signal back into a physical sound, which is what you hear coming out of the amp.
Preamps and power amps can either be solid-state or tube powered. The main thing to consider in your selection of an amp is what kind of tone you are after. Sounds simple, but you really need to spend some time thinking about this before you go out and buy an amp. In a nutshell, tube-amps create a rounded tone, which will appear as a sine wave if you analyze it. Solid-state amps create a square wave, which is an edgier, crisper sound.
A good example of a tube-amp sound would be Carlos Santana’s flowing sustain, or Stevie Ray Vaughan’s “fat” tone. For solid-state tone, imagine Andy Summer’s tone from his Police days, or the edge and nastiness of Dimebag Darrell’s riffs (Pantera).
Think about the guitarists you like, then decide if you want to try to emulate their tone. A quick search online will usually pull up detailed descriptions of what gear your favorite guitarists use to create their signature tones. Amplifiers are usually configured in one of four ways:
- Solid-state pre- and power amp
- Tube pre- and power amp
- Hybrid: tube preamp, solid-state power amp; solid-state preamp, tube power amp.
- Line6 Spider III (great practice amp!): all solid-state
- Marshall JCM2000: all tube
- Marshall AVT series: tube pre-, solid-state power amp
- Line6 Pod XT Live/Mesa Simul-Class 2:Ninety: solid-state pre-, tube power
The Line6/Mesa rig is what would be called a modular or rack setup. Each unit is designed to be screwed into rails inside a rack. The other two configurations of amps are called combo amps and stacks.
A combo amp contains the preamp, power amp and speaker(s) all in one enclosure; generally these amps are smaller than stacks. Stacks separate the amp and the speakers, so your preamp and power amp are in one unit (called a head) while your speakers are in heir own enclosure (called a cabinet).
Rack units are the most versatile setups, allowing you to use any number (and brand) of preamps, power amps and speakers in all sorts of combinations; of course, more options usually also equals more money. Using an amp head gives you the option of using different cabinet setups: a two speaker cabinet for a small club, four speaker cab for a bigger gig, etc.
A small combo amp is great for practice, but many performers also use them live because they can’t find a particular tone anywhere else; for example, a Fender Twin. There are way too many combinations to cover in detail in this little blog, but hopefully this will help you start narrowing your search.