Amplifiers

The term "amplifier" is actually quite imprecise, as there is a difference between preamps and power-amps. The actual sound impact and tone arrangement take place in the preamp. The power-amp generates the required capacity that drives the speaker without forming the tone essentially.

If the preamp and the power-amp are in the same box as the speaker then it is referred to as a "combo". If the preamp and the power-amp are in a seperate box than the speaker, then it is called a "top" or a "head" because it is actually placed on top of the speaker later.

The technical development of the first guitar amplifier has generated different technologies which exist next to each other today:

Solid State

The first guitar amps built in the 70s were without tubes and did not have the best reputation. Although they were light-weighted and due to the low heat build-up less fragile and cheaper in purchase, the sound alone couldn´t satisfy. In the meantime the solid-state technique has caught up a lot and due to their tricky switching they hardly differ in sound from tube amps. A lot of the major manufacturers have both transistor amps as well as tube amps in their product range. But what´s important is the end-volume of transistor amps is a lot lower than that of tube amps with the same output.

Hybrides

Hybride amps are those amplifiers where both transistors and tubes are used. Most of the time only one tube is put in the preamp to form the sound whilst in the power-amp transistors are used to reduce costs and weight. The aim is clear: The advantages of both technologies are combined.

Modeling/Digital Technique

In modeling-amps there is a computer that works in the preamp which can authentically recreate the sound of well-known amplifiers digitaly. This technique is so well-engineered that it is often used in studios and on stages. It offers the possibility to store several different sounds and trigger them off when needed.

Grand Channel

Channels are the name for the preamp section of guitar amplifiers and their resulting number of possible and mainly per foot pedal triggered sounds. Up into the 70s guitar amps had a seperate plug for the different channels so that multiple musicians could play through one amp. Today this is only possible with reissues of classic amplifiers. Channel amps are also accepted, as they often react very sensitive to the gutar or effects connected.

Combos vs. Stacks vs. Racks

The combination of an amplifier and speakers in one box is not only highly recommended because of transportation reasons, but also because of the sound that is sent out of the rear entrance and spread into the room smoothly. If you prefer the compact, often more pressing sound of closed boxes then its best to choose the so called "stack", a combination of an amp-top and boxes which are not only approved by hard-and-heavy rockers. If you chose preamp and power-amp seperately and combine them with studio effects of the 19"-format then you have a "rack-system" - a very individual and variable way of amplifying your guitar; popular in the 80s and 90s.

Which box for which sound?

Whilst speakers with closed rear boxes offer the more compact and pressing sound, speakers with open boxes often sound "open" - like their name already suggests. For the sound volume two other features are also of importance, namely the size of the box and the complete surface. The thumb rule is that the sonority grows with the number and size of the speakers and the box volume whereas small speakers have a faster and more dynamic responsiveness and often offer a finer resolution. The diameter is usually measured in inches. Typical standards are boxes with two or four 12-inch speakers for powerful hard-and-heavy sounds, compact boxes with a 12-inch for solo sounds and boxes with two 10-inchs which create both clean and pitched sounds perfectly.