This article was written to shed a little light on the popular combo amp, who would use one, and how to pick out the right one for you.
Combo, Head, Cabinet... What's The Difference?
You could write an entire article about the difference and benefits of each of these, but I'll touch on it briefly.
First, the basics. To hear your guitar any louder than you would hear it acoustically, you need it amplified. A guitar amplifier is an electronic device that amplifies your guitar's sound - nothing more. A set up that lets you hear your amplified guitar sound is made up of two main components - amplifier and speaker(s).*
Here are some terms to keep in mind:
Head - This is a stand-alone guitar amplifier that has no speaker. It's called a head because, well, it sits on top of a speaker cabinet and sort of represents the "head" of the setup. Playing through a head alone will produce absolutely no sound unless it is connected properly to a speaker cabinet. You should also know that an amplifier doesn't need speakers to be considered an amplifier. You won't hear anything without speakers, but it is still an amplifier.
Cabinet - This is a stand-alone cabinet containing nothing but speakers. Playing directly into a cabinet will produce absolutely no sound since you have nothing to amplify the guitar signal. You can get speaker cabinets in various combinations. A 4x12'' cabinet will have four 12-inch speakers, a 2x10'' cabinet will have two 10-inch speakers, and so on. 12-inch speakers are the most popular and most recommended for guitar, though some people like 10-inch speakers for their tight low-ends. Your typical "Marshall Stack" is made up of a head and one or two 4x12'' cabinets.
Combo - This is one unit containing both an amplifier and one or more speakers. This is commonly referred to as simply an "amp". Your typical practice amp is usually a combo. Think of the many smaller Fender, Marshall, Peavey, Line6, Crate and other combos amps you frequently see in music stores. Most people's first amps are usually combo amps.
*You can get more technical about pre-amps, power amps and rack units, but that's not the focus of this article.
Most people buy combo amps because they're easier to use and, in general, more compact. A good combo amp can be used to practice, record, gig and even tour with. They also look cool and make for less equipment to move around. BUT - depending on which combo amp you get, it's not necessarily lighter or easier to carry around. Try carrying a larger combo up and down tight stairs and lifting it onto a four-foot stage, and you'll see what I mean. It may also not be any cheaper.
Choosing a head/cabinet or combo setup is a matter of needs and personal preference. Many pros opt for the head/cabinet setup since it allows them to use one brand or type of amp with any speaker cabinet(s). This makes their equipment much more scalable and versatile. You can always (usually) run your combo amp through another speaker cabinet for more volume, if that's needed. Some pros actually tour with combo amps. Santana and Incubus are two that come to mind that have used combos for touring.
There are many good quality amps around, and everyone you talk to will have a different preference of brand. I can tell you I've been playing over 20 years both pro and semi-pro and have played a ton of different amps. I've been lucky enough to use a lot of different amplifier setups in a lot of different situations.
As far as pricing, you should expect to pay at least $500 or more on a decent combo. A good amp that will sound much better, be as loud as you need it to be, and last a long time will run over $1000. Some higher-end combo can run easily run over $2000. You can find amps that are cheaper new, but you'll usually be sacrifing really good sound, or tone, for cheaper speakers and other shortcuts and quality-cutters to keep the price low.
My suggestion is the buy the best amp you can afford. Whether you're a bedroom jammer, a garage band, a working musician or a professional touring act, you'll want to be happy with the amp when you play it. I've seen people (including myself) spend hard-earned money on a new amp, get all geeked-up about it, only to be disappointed with it shortly after buying it or when you really need it. Trying to be cheap and save money by getting a bargain amp will only frustrate you when you can't get the tone you want, when it breaks down, or when it won't get loud enough to be heard. By all means try to get the best price for that good amp, just don't buy a cheap amp.
If your budget only allows so much, that's fine. Just keep in mind that you're probably buying a low-quality amp and can't expect much out of it. Keep in mind that you do get what you pay for. Don't kid yourself into thinking that a $500 amp is going to sound as good as a $1500 amp, because it will not - no matter what the ad says or what the salesman tries to tell you.
You might hear from other player that have a low budget or that are just hobby players that you're only "paying for a name" or that their $400 amp is just as great as some $1,700 amps. This is certainly not that case. Any experienced player can tell the different between a high-quality amp and a cheap amp in about minute. A beginner, hobby player, or someone that just doesn't know quality won't be able to tell any different. Just as a Ford Escort will not drive and handle like a BMW 535i. Sure, both can take you to the same place, but the style and quality of that ride is not even comparable.
If you're someone that can't tell the difference, then by all means get the cheap amp.
It's important to keep in mind that although 100 watts is 100 watts - no matter what the brand or model is, wattage and usable volume are two different things and don't necessarily have a lot to do with each other. Basically solid-state amps won't get as loud as their all-tube counterparts. The ones that do get as loud will be shrill and poor sounding, although the decibel level might be equal. Think of an AM radio cranked to 10. This is important to keep in mind if you are looking at a 100 watt solid-state amp.
Example: My old 100 watt Marshall VS105R Valvestate 2x12 ($580) combo could get some great tones with some EQ tweaking at lower to moderate volumes. It was loud enough to play a lot of smaller bar gigs, but the actual tone at that higher volume wasn't that great. My 50 watt Mesa-Boogie Rect-O-Verb 1x12 ($1400) combo sounds MUCH better and gets at least twice as loud as the Marshall and sounds even better at higher volumes.
What? How can that be? It's a little to in-depth and technical to mention here and there are many other articles you can read online about this. The bottom line is that a good 50 watt all-tube amp is about as loud as a 200-250 watt solid state amp AND sound a whole lot better.
You could sit and discuss this all day. My opinion (and that of many other experienced guitar players) is this: Solid-state amps can sound pretty good sometimes. Their cleans are usually pretty good and their distortion is sometimes not bad. A good all-tube amp can sound absolutely GREAT and inspire you to play more, play better and get ideas you'd never think of otherwise. NO solid-state amp can sound exactly like a tube amp. This is most noticeable when you play a high-gain pinch harmonic. Sound-wise, tube amps are far superior in volume, sound and feel. That said, some solid-state amps can be a good place to start and can be good, reliable gigging amps for a low budget.
Some brands I would recommend for good quality solid-state amps are Marshall, Fender, Peavey, Line 6. Crates are cheap but sound thin and lifeless to me, but that's a personal thing. I've never heard a Crate I liked - solid state or tube.
Some good all-tube brands would be Roland, Peavey, and Fender.
Some better all-tube brands would be Marshall, Rivera, Soldano and my personal favorite, Mesa-Boogie.
Dumble, Diezel and Bogner make some excellent hand-built boutique amps, but will run you anywhere from $2300 to $12,000 +. Well worth the money for a professional that wants a certain tone, if you've got that cash to begin with.
Some amps come with a ton of features and effects. Some you want and some you should avoid. Having a foot-switch that lets you switch between clean and overdrive is pretty much a must. Having a bunch of effects like chorus, delay, reverb, flangers, phasers, harmonizers and such all into one amp aren't necessary a good thing. Most amps will have reverb which you should use sparingly. Many people use this way too much and it can sound real bad for most things. If you want extra effects like chorus, flanger, delay I would recommend buying a separate multi-effects unit or separate foot pedals. An amp that has too much crap packed together has more problems that can go wrong with it and is probably sacrificing a great tone for these extra features. I would much rather prefer to have two or three great tones than 1000 half-ass ones.
Another side note would be not to rely too much on effects anyway. A good amp with a great tone will make you NOT want to use any effects since it sounds so great by itself. If you hear someone playing with a tone of chorus and delay for everything, it's usually to hide the sound of a cheap amp or because they just don't know any better. I usually think of amateurs or beginner when I hear someone using too many effects. When you have access to a lot of effects it's real easy to want to use all these cool-sounding things whenever you can, but it takes away from your playing ability and puts you in a tough situation should your effects not be available or crap-out on you during a gig. Plus, many multi-effects units have about 4 or 5 usable effects and a ton of stuff you'll never really use. Sure, it'll be fun to play with in your bedroom, but you'll never really use it.
On another note, if whatever you're playing doesn't sound good totally clean or on an acoustic, there's probably something lacking musically that can't be "fixed" with any amp or effects.
The best way to test an amp out accurately is to use YOUR guitar on it. Play a little bit of everything on the amp - some picking, some strumming, clean, overdrive, leads, palm-muting, low-string leads. Make sure this amp sounds good for all the different things you play now and plan on playing in the future. You can weed out a lot of muddy amp buy setting some overdrive on the amp and palm-muting some low-string leads. You should be able to hear each note very clearly.
If you are in a band, it helps to test it out at practice. Make sure you can be heard over the drums and bass and that everyone including yourself likes the tone at that level. Most places give you a 10-day return policy if you don't like the amp, Guitar Center gives you 30 days. It's a good idea to be VERY careful with it for the return period or until you know you want to keep it. They won't take it back scratched or scuffed up.
You should really resist the urge to load a bunch of stuff (cords, power strips, pedals) in the back of the amp. This can mess up the reverb tank, the tubes, punch holes in the speaker, etc. I've done this a few times when I first started playing. Do yourself a favor and just use a gym bag or something. You have more room and you won't have to worry about your amp. I use a backpack with a lot of pockets. There more than enough room for everything, I can put extra strings and picks in their own spot, it's easy to sling over your shoulder and you can get cool-looking ones pretty cheap at Target or WalMart.
You'll want to keep extra strings, string winders, picks, extra cords, you own power strip (with a breaker if possible), tuner and 3-prong adapters when you gig or practice. I would NOT recommend ever using a 3-prong adapter and to make sure your amp is ALWAYS grounded properly, but something that's just not available. Always carry a spare set of tubes if you have a tube amp. They usually come in a padded container so you don't have to worry about them breaking. I would also recommend getting in the habit of using a guitar stand. I cringe every time I see someone stand their guitar against something with the neck holding itself up. They can easily fall or put too much strain on the neck. You probably don't want to have a cracked neck from the guitar falling over. The $10 investment is WELL worth it.
Hobbyist: - Wants something decent-sounding with lots of feature/effects to play with. Would sacrifice volume and tone for features, ease of maintenance and price. - Get 20-40 watt solid-state amp with onboard effects. One speaker would be fine. Some brands are Crate, Fender and Line 6. Should find a lot for under $350.
Garage band: - Wants a cheaper, but decent sounding and loud amp. - Get a 100 watt solid state or 40 watt tube amp. One or two 10" or 12" inch speakers. Some brands are Fender, Marshall Valvestate, Randall and Line 6. Should pay $350-$1000.
Working musician: - Needs a good versatile sound, durability and reliability, volume. Will most likely have this amp a long time and will be used in a lot of situations. - Get at least a 100 watt solid state or 50 watt tube amp. Two or four 12" inch speakers. Check out a Marshall, Fender, Mesa-Boogie. Expect to pay $600-$2000, depending on how much you're into your tone and equipment.
Professional: - Must have the ultimate tone, great reliability, durability, volume and high quality. Needs great customer support for amp. Amp can last a lifetime. - Get at least a 50 or 100 watt all-tube amp. Two to eight 12" speakers - probably on 4x12 cabinet (large shows) and one 2x12 cabinet (smaller shows and recording). You're going to spend $1500+. Look into a Mesa-Boogie, Soldano, Bogner, Fender, Marshall, Dumble or Diezel.
A lot of different factors should help you make your decision - tone, features, price, quality, durability, volume, versatility. You should be happy with whatever you pick. If you can find a cheap amp that does what you want it to and makes you happy, go ahead and buy it. Most experienced musicians need to hear a great tone and want a high-quality amp that will literally last a lifetime if they want to keep it around.
The tone of the amp should make you smile and make you want to play it all day. It should inspire you to create things you normally wouldn't have though of. If you can wait a little longer, you may want to save a few extra bucks for the higher model with the better tone - you'll never be sorry.
I've played guitar for about 26 of my 35 years, and have played in many different situations with hundreds of different musicians. I've written, recorded, performed all styles of music, as well as having scored soundtracks and TV commercial jingles. I am a real stickler for tone, and have learned a lot over the years.
The Bottom Line - Make sure it makes you smile when you play it. That's the most important thing!