How to Choose a Guitar Amp

2024 Author: Samantha Chapman | [email protected]. Last modified: 2023-12-17 09:13

If you are looking for a guitar amp, but are unable to understand the subtle differences between tubes and transistors, EL34 vs 6L6, or between British and American sounds, choosing what to buy can be a daunting experience. What is meant by "mellow sound"? All of this might rather make you want to grab a ukulele and move to Hawaii! Here, before making such a drastic decision, take a few minutes to read this article.

Steps

Part 1 of 6: Basics

Step 1. Use your ears

Of course, it sounds absolutely simple and totally empirical and there really is no acronym to cover the subject. However, it is essential to realize from the outset that you should like the sound of the amplifier based on the style of music you play.

• A Marshall amp sounds amazing whether your style falls into that of Van Halen, Cream or AC / DC.
• A Fender amp sounds decent too, if you want a sound closer to Stevie Ray Vaughan, Jerry Garcia or Dick Dale.
• The best way to determine the sound of an amp is to plug in your guitar and play. If you're a beginner and don't have a lot of confidence in what you have, but still want an amp to get used to, find a shop assistant to try it out for you. The critical issue is rather how to compare the tone of amp "A" with that of amp "B", so go out of your way to get a good comparison.

Step 2. Assess your needs

Amps are rated based on power, rather than physical size (although high power ones tend to be bulkier).

• Low power tube amplifiers: tend to create harmonic distortions at lower volumes, a feature that is preferable for rehearsals, in the studio or to be miked on stage.
• High power tube amplifiers: create distortion at higher volumes, which requires a more creative approach when mixing in live situations.
• Power affects both the actual and perceived sound volume. In general, 10 times more power is required to double the volume of the perceived sound. For example, the perceived volume of a 10-watt amp will be half that of a 100-watt one.
• Power and price are rarely related; In fact, on the market you can find 10-watt amps that cost 2, 3 or even 10 times more than a 100-watt one: it basically depends on the quality of the components and the design. An imitation of a 100W transistor amplifier is significantly less expensive to produce than an original 5W tube.

Step 3. Try to understand the elements that define the overall sound performance of an amplifier

The sound quality achievable from an amp can be determined by a variety of factors, including (but not limited to):

• The tube preamp used;
• The tube amp used;
• The wood used to make the cabinet;
• The type of cone used for the speakers;
• The impedance of the speakers;
• The guitar used;
• The cables used;
• The effects used;
• The pickups mounted in the guitar;
• … The guitarist's touch!

Step 4. Learn the categories

There are two main categories of guitar amps: combo and head / cabinet.

• The "combo" amps combine the electronic part of the amplification with one or more speakers in a single solution. They are generally small in size, as combining robust power with a pair of large loudspeakers can easily push an amp into the "weightlifting" category.

  

• Headboard / cabinet solutions solve the weight problem by separating the speaker cabinet from that of the headboard (the amplifier). The heads can be a separate mobile unit that is generally placed on the cabinet, or they can be mounted in a rack unit (very useful on tour and more suitable for more complex wiring in terms of handling the signal generated by the guitar).

  

Part 2 of 6: Tube and Transistor Amplifiers

Step 1. Compare tubes versus transistors

There are substantial differences between the two types of amplification. Tube amps use tubes in both the preamp and power stage, while transistor amps use transistors throughout the chain. The result often translates into decidedly different sounds.

• The transistor amp they are known for having a bright, clean and accurate sound. They respond well to your playing, and are much "harder" than the tube ones; to get an idea of the concept you can think of the difference between a filament bulb (tubes) and an LED bulb (transistor); if you throw them on the floor, the first one literally explodes. Also, with advances in technology, many transistor amps are able to offer, in the same configuration, a wide range of simulated sounds than other amplifiers which results in great versatility.

  

• Transistor amps from certain manufacturers tend to have the same loudness, which is beneficial when you need to be able to rely on this kind of reliability. They are also significantly lighter than their valve counterparts, in weight and for the wallet.
• Versatility and "hardness" come at the expense of the warmth of the sonority. While this type of evaluation is totally subjective, there are some differences to be aware of: when pushed into distortion, the waveform of the signal generated by the transistor amps shows sharp cuts and the harmonics remain strong throughout the range. acoustic. When a tube amp is pushed to distortion, the waveform instead presents softer cuts which, together with the gradual decrease of harmonics within the limits of the acoustic range, makes the sound warmer, a characteristic of this type of technology.

• The tube amp they have that indefinable "something" that makes them the most popular type of amp. The sound of a tube amp is described as thick, mellow, robust and rich, adjectives that would put on a few pounds if amps were food!

  

• The sonority of the tubes can vary slightly from one amplifier to another, and definitely between different guitarists. For some players, their amp is the element that, together with the guitar, defines their sonic identity.
• The tube distortion is softer, and much more pleasant to listen to for many, and when pushed to extremes, it adds a bit of compression to the dynamics which gives the sound that sonic richness that only tubes can provide.
• Tube tubes can be much more powerful than their transistor counterpart. A 20W tube amp can easily sound like (if not better) a 100W transistor.

Step 2. The drawbacks of tube amps are generally more practical than sound-related

A tube amp - especially a large one - can be very heavy indeed - a big drawback if you have to regularly haul your rig up three flights of stairs!

• Tube amps are also more expensive, both initially and when it comes to maintenance. A transistor is simply what it "is". Unless there is a large voltage surge, your transistor amp will keep the same sound over the years. The tubes, on the other hand, just like incandescent bulbs, wear out over time and at some point you will need to replace them. While not excessively expensive, it will still be an annual expense to take into account (based on usage).
• Tube amps rarely have effects. For this type of thing you will need a pedal board. However, tremolo and reverb can often be found incorporated.

Step 3. Beware of prejudices

While it's good to know the pros and cons of both amp types, it's not always true that "tube is better than a transistor system". Industry research shows that, played without distortion, they are both virtually indistinguishable.

Part 3 of 6: Combo amps

Step 1. Check the options for the combo amps

Here are some of the more common configurations:

• Micro amplifiers: 1 to 10 W. They are very small, super portable and very useful for exercising (especially when others try to sleep). They are not suitable for "jam" situations (they cannot get enough volume to stand out overall when you play with other musicians). They usually have poor sound quality (when compared to larger amps), due to low output power and inferior quality of internal circuitry. The use is not congenial for professional performances. The Marshall MS-2 is an example of a micro amp (1 watt) that has received good reviews for this size of transistor amp.
• Practice amplifiers: 10 to 30 W. These types of amplifiers are also fine in an environment such as your bedroom or living room, although with those that manage to offer a higher volume it is possible to use them for small concerts, especially if they are miked (the signal it is picked up by a microphone, suitably positioned in front of the speaker, connected to the general amplification system). Among the most popular in this category of amps (which sound good or even better than many larger amps) we can find the Fender Champ, Epiphone Valve Junior and Fender Blues Jr. Usually, the best amps in this group have among the 20-30W with at least one speaker with a 10-inch cone.
• Standard 1x12 combo: they start from a power of 50 W and have at least one speaker with a cone of at least 12 inches; this configuration is the smallest option suitable for an evening in small rooms without the need to add a microphone. For the most prestigious models, such as those produced by Mesa Boogie, the sound quality is superlatively professional.
• Combo 2x12: similar to 1x12, but with a second 12-inch cone. Their design is considerably heavier and bulkier than the 1x12, but is the preferred choice of professional musicians for medium to large venues. The addition of a second speaker allows for particular stereo effects, and the fact that they move more air than just one translates into more "presence" of sound. Among the favorite models in this category we find the Roland Jazz Chorus, which offers a very distinctive clean sound, typical of this amp, stereo, and of the built-in effects.

Step 2. Please note:

small combos are often preferred in studio sessions. For example, if you want to know what a little 5W Fender Champ sounds like, listen to Eric Clapton's guitar in "Layla"!

Part 4 of 6: Heads, Boxes and Cabinets

Step 1. Learn about the options provided by heads and cabinets

While combo amps are great for an all-in-one solution, many players like to customize their sound. They may love the sound of a Marshall bass drum, for example, but only when driven by a Mesa head. Others may not have that kind of preference, but they want to be able to link several together, in order to get a powerful wall of sound that takes up the whole stage.

Step 2. Learn the lingo

A head is an amplifier without the speakers. A speaker is the "container" of the speaker, which is connected to the head. A cabinet is the assembly of the head connected to a set of speakers, ready for use.

Cabin cruisers are generally preferred for gigs rather than practice, although there are no specific "rules" against having one in the living room - if the family allows it. A word of warning: in most cases they won't let you. The cabin cruisers are physically bulky, very heavy and very powerful. They represent the choice of musicians who play in big events

Step 3. Put them together

The heads are all roughly the same physical size, but it is possible to find them in different power cuts. Small amps between 18 and 50W or standard heads, generally around 100W or more. There are also super tested that can even reach a power of 200/400 W.

• For playing in small to medium sized events, a small head is more than enough. They are often connected to a single 4x12 speaker (which contains 4 12-inch cones, as the name suggests). This type of solution is known as a "half cabinet" and is the most commonly adopted option among musicians.
• Before you buy a half cab, keep in mind that they are bulky and too tall for most venues that have a small stage (most nights you will actually play), too big to fit in vehicles smaller than a pickup or minivan, your "colleagues" will not help you drag it onto the stage and, just to complete the picture, they will cause hearing disturbances (unless you use ear protection). This amplifier solution offers enough volume and the "presence" of the four speakers. Use a professional header.
• A "standard cabinet" is the dream of many guitarists (although the sound engineer and everyone on stage will not be happy about it). Generally it is characterized by a head of at least 100 W connected to 2 4x12 speakers. The speakers are stacked vertically on top of each other, thus giving the configuration its particular name (“stack” in English).
• A full cabin cruiser is as tall as a grown man and is quite impressive to look at. The sound is equally impressive. It is also too big for all kinds of events except the really huge ones, and even then it will be appropriately miked by the sound engineer; as a result, in effect, you will never use it at its peak performance. Most professional musicians tend to use two half cabs in stereo rather than carrying a full one.
• Some particularly sadistic (in the sense of sound) guitarists, especially among heavy metal players, might just be the ones who use one of those super 200/400 W heads in the "full cabinet" solution. In any case, with each of these types of cabinets (especially in the ultra-high versions) hearing protection is absolutely necessary if you intend to play at higher volumes, so as not to suffer potentially serious hearing damage.
• In many of the live concerts where you literally see a wall of cabinets, this is nothing more than a trick. Typically the one with the speakers is only one, all the others are just a scene. Motley Crue, for example, used to create false speaker grids by cutting out black fabric and 2x4 speakers to give the illusion that the stage was full of cabinets!

Step 4. Do as the pros do

Many of them use 2x12 or semi-cabinets so you can control the sound more easily. Obviously, no one prevents you from buying a complete cabinet, but you will not have the actual opportunity to use it at maximum performance, unless you do high-level concerts (stadiums and the like). Too big to be practical.

Part 5 of 6: Rack Units

Step 1. Use racks

Many players use rack devices, usually a reinforced metal box with removable front and rear panels. The front, when open, has two vertical rows of aligned screw holes on the sides, 19 inches apart - the standard size for this type of situation.

• Just like head-and-cabinet setup, a rack-and-go sound system involves separating the amplifier from the speakers. In any case, heads mounted in a rack can be divided into two categories: the preamplifier and the power amplifier. Tested and combined have these components as well, but rack units make the situation more practical by treating them as separate elements.
• Many manufacturers offer rack-mount equipment: Marshall, Carvin, Mesa-Boogie, Peavy etc.

Step 2. Preamplifier

This is the initial stage of the amplification: in its basic form, a preamp raises the signal so that it can actually drive the amplifier stage. Those of a certain level offer a variety of sound shaping options, including equalization, different tube configurations, and much more.

Step 3. Amplifier

Connected to the pre, it takes the signal modeled by it and amplifies it so that it is able to drive the speakers. As with the heads, the power amps are available in different cuts, from a minimum of 50W to monsters of 400W.

You can bridge all the amplifiers you want, or maybe connect them to the output of different preamps in order to further push the signal strength, as well as the possibility of mixing together the different sounds of different amps

Step 4. Evaluate the drawbacks of rack systems

You probably got there on your own: Racks are often complicated systems. A novice guitarist might get confused. They are also heavier and bulkier than the heads, which adds to the bulk of the rack itself. Since you will need to buy a variety of products and accessories, the price for a new rack system can often be higher than for a single header.

Step 5. Evaluate the benefits

A rack allows you to combine instruments from different manufacturers and, as a result, gives you the chance to get your own stamp! In addition to pre and power, there is a variety of exceptional products that can be mounted in the same rack: reverbs, delays, parametric equalizers and a host of other sonic delights.

• Racks are often equipped with wheels, which makes transport easier; another advantage is to have all the components already assembled and ready to use, once the rack is placed on the stage.

  

• Finally, not everyone uses racks, so having one on stage is always a nice eye-catcher. You will certainly make your figure, if you show up at the rehearsal or concert pushing one; However, make sure you are particularly good (or at least know how to use it): everyone will expect you to be a skilled guitarist. Avoid carrying it around unless you know exactly how to set up all that gear to shape your sound. All great guitarists have a personal system in tow; among these we find Robert Fripp, The Edge, Van Halen, Larry Carlton… just to name a few.

Part 6 of 6: Choosing the Right Sound

Step 1. Understand how different amp types fit different styles of music

For the most part, just one type of amp isn't suitable for all situations. Although there are an infinite number of them, amplifiers are classified into two broad categories: "vintage" and "high-gain".

Step 2. Choose the amplifier that best suits your needs

Every genre of music, especially rock, has a distinctive amp type. Here are some general guidelines:

• The vintage amp produce the classic tones of the first amps. For guitarists who play jazz, blues and rock-blues, the vintage sound is still considered the most appropriate for these musical genres. These amps can be genuine antiques or be modern and produced with circuitry that replicates the sound of vintage amplifiers. The sound of the Fender, Vox and Marshall amps of the 50s, 60s and early 70s is considered the quintessential vintage tone. When you think of vintage, Hendix, Led Zeppelin, Eric Clapton, Deep Purple come to mind… these are the sounds from which it all started.
• The high-gain amp (high gain) produce a sound with more distortion than previously seen. Although origin and evolution are still debated, many believe that much of their story is due to Eddie Van Halen. In fact, Eddie didn't have much experience with electronics (admitted by himself: this explains why his guitar was a little off the norm for the period), all he did was just put all the knobs of his amplifier to maximum and then control the volume with a variac, in order to decrease the voltage. With the solo of "Eruption", in 1977, he introduced the whole world to the roaring sound of an amp with tubes pushed to the maximum. Amp manufacturers have begun to emulate that sound at lower volumes, and then have begun to add more gain stages to the preamps at the design stage, in order to achieve a higher gain sound, but with more controlled volumes. With the development of heavy metal, the need for this type of amp has increased exponentially. Specifically then, as far as hard rock and heavy metal are concerned from the 1980s onwards, vintage amps have been outclassed, so to speak, by their more modern counterpart.
• If you want to play jazz, blues, blues-rock (like Led Zeppelin) or more classic heavy metal (like Black Sabbath), a lower gain tube amp is the best choice. If you want to play hard rock, 80s metal and grind the guitar instead (in the style of countless "guitar heroes"), your best bet is probably to go for a high-gain model. However, keep in mind that many of the new products are capable of offering both types of sounds, although more "traditional" players are still convinced that the true vintage sound comes exclusively from a vintage amplifier.
• Amp modeling technology (which allows one amplifier to emulate the sound of others) is a relatively recent new approach that appears to have both supporters and critics; for many, however, this type of amplifier has a decidedly appreciable sound. Sure, they can be very useful (and often cheaper too), but if you're a purist, nothing beats a real Fender Twin Reverb, Vox, or vintage Marshall head.

Advice

• Unless you're playing pure black metal, it's generally better to buy a smaller amp with a good sound than a big one with a cheap sound. You will never have any regrets if you manage to get a nice stamp… unlike the other way around. Some musical instrument shops may try to entice you with amps with lots of effects, especially if you are a newbie, but avoid falling for them. Use your ears and choose an amplifier that you absolutely like, trying not to spend anything until you find it.
• If you decide to buy a transistor amplifier, avoid always pushing it to the maximum. Don't be afraid to turn the gain knob to the maximum, but be careful of the effects you put before the amp: you risk burning the transistors. If you buy a tube, having a boost at the amp's input is not a problem; tubes are typically capable of handling a ridiculous amount of signal.
• If you buy a tube amplifier, avoid physically mistreating it. In general, transient amps are more durable, while tube amps are much more delicate. If your very expensive new tube Soldier, just bought, flew down the stairs, you'd be in trouble; if the same thing happens to a transistor combo, the result is probably nothing more than a little momentary panic and a few laughs (later). If you're wondering what the reason for such a warning is, you've probably never spent so much time with rockers.
• For most guitarists, a 30W amp is more than enough to keep in the room, for practice and rehearsal, or for playing in small venues.
• If you need an amplifier that works for all situations, consider purchasing one with an emulation system and built-in effects. The high-end ones are able to reproduce the sound of so many other models with good accuracy, and also offer instant access to a full chain of effects such as delay, chorus, flanger, reverb etc. Among the most renowned brands for the quality of this type of products we find Line 6, Crate and Roland.
• When looking for an amplifier, price shouldn't be the only thing to consider. Some cheaper amps still deliver a great sound, while among the expensive ones you may not find one that fully satisfies you. Reading reviews or doing some research online at specialized sites could help you make the final decision.
• Always try, before buying. Most musical instrument stores offer outstanding service for the sole purpose of making you a satisfied customer; if they don't offer it to you, chances are you can find the same thing in a different store. Reading reviews is not enough; nothing beats trying the amp yourself. Take your guitar with you and ask if they let you try any amps. In most stores you shouldn't run into any problems, otherwise just think it's not worth it and look elsewhere.
• If you want to have a great variety of sounds, your best bet may be to buy a good quality multi-effects pedal (the kind that emulates the sound of amplifiers). Then, you can decide whether to buy a good amp (transistor or tubes) or simply use the speakers of your PA system during the evening, or, if you can really afford it, buy a digital processor like the AXE FX from Fractal Audio.

Warnings

• Before playing into a tube head, always make sure it's plugged into a speaker. Without the speaker load, you would damage the amplifier.
• Be sure to do your research and be wary of some vendor reviews (often they are nothing more than commissioned advertisements that are meant to boost sales).
• Buying a big combo amp (or cabinet) with the sole purpose of blasting your living room at all times… could lead to a divorce. Likewise, even spending a lot of money without consulting your wife first.
• Keep the volume low when practicing at home. Using headphones is a great idea. Likewise, if you plan to buy a large Marshall cabinet for garage testing; make sure the garage walls are detached from the rest of the house … your wife may not like having windows shaking too much when entertaining her friends in the living room while your band rehearses Black Sabbath's "War Pigs".
• If you always play with the distortion throttle at full throttle and the volume at maximum, make sure the speakers are designed to handle it.