An audio distribution amplifier (DA) is designed to reproduce the same audio signal to multiple outputs. Unlike an adapter cable that simply splits the audio and produces a weaker signal output, a distribution amplifier ensures the same signal strength that goes into the unit also leaves the unit for each output. Recording studios, media production companies, and complicated home theater installations typically will use an audio distribution amplifier to route a common audio source to many locations.
Though the design of audio distribution amplifiers changes with new technologies, their role of providing the same audio signal to a number of destinations remains essentially the same. They can be used for feeding the same audio to a number of tape duplicators, distributing audio throughout a home or business, or with an audio kiosk that allows a number of headphones to connect to the same audio source. Professionally, they can be found providing the same audio to a variety of components used in a recording studio.
Generally, an audio distribution amplifier is designed according to specific purposes. Some use inputs and outputs that require raw wire to be attached with small retention screws or the same kind of connectors found on speaker components. Others are manufactured using specific kinds of audio connectors, such as balanced three-pin XLR or unbalanced Radio Corporation of America (RCA) jacks.
The internal circuitry typically will reflect the kind of application for which the distribution amplifier is designed. Some distribution amplifiers provide only a few additional outputs, while others provide dozens of outputs. Generally, the more outputs provided by a distribution amplifier, the more the device will cost.
Additional features may include the ability to apply gain, or increase the volume, for the entire unit or for each individual output. An audio distribution amplifier used for professional audio installations typically uses high quality electronic components that maintain the original quality of the audio signal. Poorly manufactured units may add noise or unwanted distortion that could degrade the audio quality.
Most distribution amplifiers are also designed to include video. Unlike audio, which can be split without noticeable degradation in quality, video cannot be split into two paths without the signal becoming unwatchable. Home theater distribution amplifiers frequently include both audio and video signal paths in the same unit.
Older units designed for analog audio have been replaced by digital models. Digital distribution amplifiers use digital audio protocols, such as Audio Engineering Society and European Broadcasting Union (AES/EBU), TOShiba LINK, (TOSLINK®), or Sony/Philips Digital Interconnect Format (S/PDIF). As audio technology advances, so does the need to bundle outputs from a single, or monophonic audio channel, to multiple audio channels used with Dolby® 5.1 and 7.1 surround sound.