One important concept in the age of electronic music is the use of the power amplifier. Amplifiers are needed to send the sound created by an instrument out into the air where an audience or the player can hear it.
In order to accomplish this, amplifier systems have been invented. There are dozens of different kinds of amplifier systems, from those found in instruments to those found in stereos and public announcement systems. Specific instruments often have an amp that is designed for them, such as a guitar amp, a bass amp, or a keyboard amp.
One of the big differences in each of these kinds of amps is the power it uses. The power is located in the head of the amp, and the places that generate the power used for the amplification system are known as power amps.
Audio power amps are included in combo amps, along with everything else. The power produced is measured in watts, which is the unit used in many electric functions. The more range or power that is needed, the greater the wattage in the power amplifier. The result might be called a high power amplifier.
This is useful to know for those musicians who prefer to design their own amplification systems. There are also several major types of audio power amplifiers. Some of the more commonly used are the stereo power amplifier, the mono power amplifier, the solid state power amplifier and the vacuum tube power amplifier just to name a few.
Measuring the power used by amps can be tricky, as there is not a proportional measurement in the power output and the decibel level (dB). Decibels are used as measurements (for the purpose of music) of acoustics, although they also apply to electric functions. Decibels are very small units, and one decibel is roughly equivalent to the smallest change in sound that a human can perceive.
Simply put, doubling the wattage of the power output in power amps will not double the decibel level. Instead, increasing the wattage by two times will increase the decibel level by 3. This is the case no matter what wattage you are doubling, be it 300W to 600W, or 100W to 200W. It is always constant.
For the musician, the measurement of the power amp is important as it directly relates to how well the instrument will be heard over other systems. Most soundboards will include equalization controls which compensate for electronic instruments which require greater power amps, such as keyboards and even basses.
As a mid-range instrument, guitar amplifiers do not require such a high power output. However, levels on the power amp of the amplifier hooked up to the guitar need to be adjusted upwards so that the guitar, including solos and rhythms, can be heard over the other instruments. Often, guitar players find that the power setting should create a +3dB in comparison with the other instruments.
Understanding the function of power amps is essential to musicians who play in bands. The power amplifier is what will produce the electric energy necessary for an instrument such as the guitar to be heard over keyboards and drums, without the instruments drowning each other out. Amps should be purchased according to the style of music that you play, and the venue you play in.