In home stereo systems and home theater sound systems, sound is reproduced by using a preamplifier and a power amplifier. Audio devices that combine the preamplifier and amplifier in one unit are called integrated amplifiers. Separate components are usually best for reproducing music, while integrated amplifiers work well for home theater systems using surround sound.
When an integrated amplifier is used, sound is first sent from different audio devices to the preamplifier. It raises the signal level just enough to send it to a power amplifier. The power amplifier raises the sound level enough for people to hear the sound. The sound is then reproduced by the speakers connected to the integrated amplifier.
Amplifiers typically include several audio inputs for different devices, such as a television, CD player, DVD player, and a satellite or cable television receiver box. Some also include inputs for tape decks and turntables. Integrated amplifiers also include outputs for speakers. Integrated amplifiers used in home theater systems usually have six to eight speaker outputs.
Some line level outputs are also included in these amplifiers. Line level output does not go to the speakers. Line level outputs include headphone jacks and tape outputs. Tape outputs are used for recording the sound that is reproduced by the amplifier.
The power of an integrated amplifier is measured in watts and ohms. Generally, more powerful amplifiers are needed to fill larger rooms with sound. The power level required also depends on the user's personal sound level preference.
Integrated amplifiers can save home theater enthusiasts money since one unit does the work of two different devices. A quality integrated amplifier can last several years. These generally require little maintenance other than external cleaning. As with all electronic devices, amplifiers should be kept away from water and areas with high humidity.
This device can also save a significant amount of time. Setting up an integrated amplifier will take less wiring than setting up a separate preamplifier and power amplifier. This can be important when home theater systems need to be disconnected and moved.
Generally, home theater systems will stay in one place. There may be times, however, when the system will need to be moved. Moving the system to a new home or another room, painting the room, and cleaning the room and sound system can require that all components be disconnected and then reconnected.
These amplifiers can usually be connected to most audio devices. As audio and home theater technology changes, amplifiers may become outdated. For example, an integrated amplifier produced in the 1990s may not be able to accommodate a Blu-ray™ Disc player.