Our Guitar Amplifier Buyer’s Guide
Just what is a guitar amplifier?
Simply put, it is an electronic device that strengthens the signal from a pick up on an electric guitar, bass guitar or acoustic guitar so that it can produce sound through one or more loudspeakers. The speakers usually are housed in a cabinet made of wood. There are basically two types of guitar amplifiers. It may be
- A stand-alone wood or metal cabinet containing only the power amplifier and preamplifier circuits requiring the use of a separate speaker cabinet
- A combo amplifier which contains both the amplifier and one or more speakers in its cabinet.
There are plenty of size variations and power ratings in guitar amplifiers. They range from
- Small “practice amplifiers” with a single 6” speaker and a 10-watt amp
- Heavy combo amplifiers with four 10-or 12-inch speakers and a powerful 100-watt amplifier which is loud enough to use in a large room.
Besides the obvious, a good guitar amplifier can also modify the guitar’s tone by emphasizing or de-emphasizing certain frequencies. This is accomplished using equalizer controls which function like bass and treble knobs on a stereo system, and by adding electronic effects, distortion (also called “overdrive”), and reverb. These are commonly available as built-in features on a guitar amplifier.
Modern guitar amplifiers have an input ¼” jack. It is fed with a signal from an electromagnetic pickup (from an electric guitar), or a piezoelectric pickup (usually from an acoustic guitar) using a patch cord or wireless transmitter.
The choice of a guitar amplifier and the settings they use on it are key factors for creating a guitarist’s signature tone. Guitarists also use external effects pedals to alter the sound of the tone before the signal from the guitar reaches the amplifier.
History Of The Guitar Amplifier
What is the history of guitar amplifiers?
Way back in the 1920’s it was not easy for a guitarist playing the guitar with a pick up to find an amplifier and speaker that would produce enough volume. The only sort of amplification available was with speakers which were designed for radio broadcasting with a limited frequency range and low acoustic output. The cone speaker, that is still used today, was not invented until 1925. Powering these speakers back then could only be done by using large batteries, thus making the amplifier unreasonably heavy.
The first loud, powerful amplifiers were invented for PA systems in movie theaters. They were expensive and enormous so were out of the question for touring musicians.
After 1927, when the AC-mains-powered amplifiers came on the scene, they were readily used to make musical instruments of all sorts louder. These were much more efficient and could be plugged into a regular wall socket. Some guitarists, notably Leon McAuliffe and Bob Willis, used a carbon mic and a portable PA as late as 1935. During the late 1920s and mid-1930s, small portable PA systems and guitar combo amplifiers were very similar. They had a single volume control and one, maybe two, input jacks, field coil speakers and thin wooden cabinets. They did not have any tone controls or even an on-off switch.
In 1928, the first company to sell an electric stringed instrument and amplifier package was the Stromberg-Voisinet Firm. Although musicians didn’t like it very well because of its not so great tone, volume, and dependability, it launched a new idea: a portable electric instrument amplifier with a speaker together in an easily transportable wooden cabinet. Then in 1929, Vega Electronics launched a portable banjo amplifier.
In 1932, Electro String Instruments and Amplifier introduced a guitar amplifier claiming high output and a string-driven magnetic pickup. They set the standard template for combo amplifiers, a wooden cabinet with the electronic amplifier mounted inside, and a convenient carrying handle.
In 1933, a big year for amplifier advancements, Vivi-Tone amplifier set-ups were used both for live performances and for radio shows. Also, Dobro released an electric guitar and amplifier package. It had two 8 Lansing speakers and a five-tube chassis. It was on the market for more than 12 years before Fender came along with its two-speaker Duo Professional/Super combo amplifier. That same year, Audio-Vox was founded by Paul Tutmarc, the inventor of the first electronic bass. Also, Vega sold a pickup and amplifier set for musicians to use on existing guitars. Volu-Tone sold a pickup/amplifier that used dangerously high voltage power to sense string vibration.
Then in 1934, Rickenbacker launched a similar combo amplifier but added metal corner protectors for protection when moving about. Gibson developed combo amplifiers that same year.
By 1935, Dobro and National were selling combo amps for Hawaiian guitars and Electro/Rickenbacker was the top seller of all amplifiers and electric guitars.
Electronic amplification of guitars, although used for acoustic amplification, came of age during the 1930s and 1940s craze for Hawaiian music. This music extensively used amplified lap steel guitars.
Enter The Era Of Effects
Early effects were very simple, with treble control at best. Fender labeled early amplifier tremolo as “vibrato”. They called the vibrato art of the Stratocaster a “tremolo bar’. Later amplifier models included an onboard spring reverb effect, one of the first being the Ampeg Reverberocket amplifier.
In the 1950s, several guitarists deliberately overdrove their amplifiers causing distortion. You may recognize the names of some of them:
- Goree Carter
- Joe Hill Lewis
- Elmore James
- Ike Turner
- Willie Johnson
- Pat Hare
- Guitar Slim
- Chuck Berry
- Johnny Burnette
- Link Wray
The Rock And Roll Era
Then in the early 1960s, surf rock guitarist, Dick Dale worked with Fender to produce custom made amplifiers. These included the first 100-watt guitar amplifier. Dick helped to develop new equipment using amplification technology that was capable of producing “thick, clearly defined tones at previously undreamed-of volumes”.
Mid 60’s guitarists got more heavily into distortion. In the 1960s we have the Gibson Lancer GA-35 guitar amplifier and U2 guitarist The Edge’s 1964 Vox AC30 combo amplifier.
Dave Davies of The Kinks connected the already distorted output of one amplifier into the input of another. Shortly after, most guitar amplifiers had preamplifier distortion controls and ‘fuzz boxes” as well as other effects built in that produced these sounds safely and reliably. This same overdrive and distortion is still used in the 2000s and is pretty much taken for granted. It works in many genres ranging from blues, rock, to heavy metal, and hardcore punk.
Technical Considerations When Buying A Guitar Amplifier
Give me some technical information. How is a guitar amplifier structured?
They generally have two amplifying circuit stages and usually have tone shaping electric circuits which frequently include at least bass and treble controls. More expensive amplifiers have more controls for other frequency ranges such as one or two midrange controls and a presence control for high frequencies. Some have a graphic equalizer that uses vertical faders to control many frequency bands. Even more, high-end bass guitar amplifiers have a parametric equalizer that enables precise tone control.
A preamplifier first amplifies the audio signal to a level that drives the power stage. High preamp signals add overdrive. The power amplifier produces a high current to drive a loudspeaker and produce sound. There are various types of tone stages that might affect the guitar signal:
- Settings on the guitar itself
- Devices between the guitar and the preamp stage, such as effects pedals, effects loops or some other dedicated amplifier tone circuits
- Between multiple stacked preamp stages (“gain Stages”)
- In feedback loops from a preamp signal to an earlier preamp signal, as in the case of presence modifier circuits
Tone stages can provide electronic effects such as equalization, compression, distortion, chorus or reverb. Amplifiers may use vacuum tubes, solid state (transistor) devices or both.
There are two common configurations of guitar amplifiers:
- A combination, (“combo”) that includes an amplifier and one or more speakers in a single cabinet
- A standalone amplifier (often called a “head” or “amp head”) which passes the amplified signal through a speaker cable to one or more external speaker cabinets
There are many speaker configurations available in guitar cabinets ranging from a single speaker (1×10” or 1×12”) or multiple speakers (2×10”, 4×10” or 8×10”). A Fender Bassman amp head has a 15” speaker cabinet.
Guitar amplifiers vary in quality and price. Imported small low-powered practice amplifiers for students and beginners sell for less than $50.00. These may be battery powered, so are perfect for street ministry or performance. The vast majority of guitar amplifiers can only be powered by plugging into AC mains (wall outlets).
The most basic amplifiers only have a few knobs such as volume, bass, and treble. More expensive amplifiers may have several knobs that control preamp volume (gain) distortion or overdrive, volume, reverb, bass, and treble. Some of the older amplifiers and their reissued versions have a vibrato or tremolo effect. The ¼” input jack is usually on the front of the amplifier and is the only jack on some of the less expensive models.
Some more expensive guitar amplifiers have a patch bay for multiple inputs and outputs, a jack to create an effects loop when used with the pre-amp. Additionally, they may have:
- An external speaker outlet for powering an additional speaker cabinet
- Stereo RCA or a 1/8” jack for connecting a CD player or media player
- A ¼” jack for connecting a pedal to turn the amplifier’s onboard overdrive on and off or to switch between channels
- Some have an XRL jack for a microphone either for the guitar amplifier to be used for singing or for acoustic guitar to mix a mic signal with a pickup signal.
- Kustom 200 Bass Amp – amp head and speakers, 100 watts RMS, two channels, two 15” speakers, 1971
- Gitka Gold Amp (“Shawn LaneAmp”} 1989 – Class A single-ended high-power 8-EL34 tube guitar amplifier that was used on Shawn Lane’s Power of 10.
Types Of Guitar Amplifiers
Which should I get, a combo amplifier or a head and cabinet?
It depends on the venue where you will be playing. For clubs or small halls or auditoriums, a combo is perfect. You will fill the room with sound. If you want to fill an open arena or large auditorium, you will need a high-powered stack with at least 4×12” cabinet and a 100-watt head. It is interesting to note, however, that some players prefer a smaller amplifier such as a Vox AC30, for its specific tone. Then they mic the amplifier and run it into a powerful PA system. A combo is an all-in-one unit, a head and cabinet are separate and definitely heavier.
Which is best, solid state or tube?
Traditional thinkers feel that the solid-state circuitry produces superior clean power and a much more affordable price while the scarcity of vacuum tube manufacturers today makes tube-based more expensive than a solid-state amplifier. Guitarists have come up with unique sounds when combining the two types. The basic tone is produced by a tube driven preamp while the power amplifier is solid state. Newer cutting-edge technology is creating amazing new amplifiers that are appealing to more and more guitarists. These are digital and there are also all sorts of hybrids. Again, it is your choice, so go with the sound you like best.
Does Speaker Size Matter?
Naturally, different sizes of speakers produce different sounds. Smaller speakers can produce higher frequencies than larger ones, which is why a tweeter is small and a woofer is large. For example, a 10” speaker will usually produce a better top end than a 15” speaker. There is also a difference between an open-backed cabinet and a closed-cabinet design.
Using This Guitar Amplifier Buyers Guide
You are now armed with much information in this, The Ultimate Guitar Amplifier Buyer’s Guide. What you have learned here will greatly help you to find the perfect guitar amplifier for your needs. You have learned all about:
- What an amplifier is and why you need one
- The history of guitar amplifiers – how they started and evolved to where they are today
- How they are structured and how the differences in structure affect the tones produced
- Different types and sizes of guitar amplifiers and how these factors affect their sound production and their convenience.
As always, you will make the final choice, but you have enough information here to make the perfect one. Enjoy learning and shopping, and then playing your favorite guitar with your perfect guitar amplifier.
Sources: Google, Wikipedia, Sweetwater Music, Guitar Center, interviews with guitarists.