Rob Sabin

Bob

A/V What?
An A/V receiver combines three audio components in one box. Primarily, it performs the traditional roles of a preamplifier and power amplifier. The sound for any home theater begins as a relatively low-level audio signal coming off a source component such as a cable box or disc player. These days, it’s more likely to be a digital audio signal than an analog signal. That signal gets converted between digital and analog as needed, manipulated to affect your volume adjustment, and might perhaps have some bass and treble contouring (or more sophisticated equalization) applied before it’s sent to the power amplifier, whose only job is to pump it up to the power level necessary to drive your speakers to sufficient volume.

In this day of dozens of HDTV channels delivered via hardwired cable or satellite transmission, it’s hard to remember that watching TV wasn’t always quite so easy. Way back when, every television had an antenna connected to it. If you were distant from the transmission tower, you might have had a big mast antenna on your roof, as did your next-door neighbor, and his next-door neighbor, and so on, until the suburban skyline came to be defined by these skeletal sculptures reaching into the bright dawn of a soaring postwar America. If you lived a little closer to the tower, you probably just used the telescopic rabbit ears poking up from the back or top of every set, and the ritual of changing channels (to another of the seven or eight available) involved walking across the room, manually clicking the TV’s rotary tuning knob, and then reorienting the antenna arms to minimize the distortion. Even then, it didn’t always work. Depending on conditions, it wasn’t uncommon to get snowy artifacts from a weak signal, or ghosting caused by multipath reception as the signal bounced off nearby buildings or other large objects.