Home Theater Receivers
An amp, pre-amp and surround processor all in one convenient package
Receivers are the multi-taskers of the home audio world. A receiver is responsible for amplification, pre-amplification and processing. Not so long ago receivers were designed for stereo systems. These were two-channel receivers or integrated amplifiers as they were both an amp and preamp simultaneously. You could hook your speaker wire to the back of the integrated amp or receiver because it had two channels of amplification built-in. You'd also connect your turntable, tape deck or whatever else you wanted amplified to round out the pre-amplifier duties of the receiver.
Soon receivers began to pop up that had built in digital signal processing (DSP) settings. They could simulate a full range equalizer inside the receiver using the latest microchip technologies. These DSP features were quickly followed with surround sound features by Dolby, such as Dolby Surround, then Dolby Pro-Logic and today Dolby Digital.
Jobs performed by the receiver.
Today's receivers perform more tasks than ever before thanks to microchip technology. They do so in the smallest amount of space and for lower cost as well. The chips that perform the processing duties required of surround effects like Dolby Digital and DTS are becoming cheaper all the time. The first Dolby Digital/DTS receivers on the market cost over a thousand dollars; today you can buy a comparable unit for under $500. You can even get a budget model receiver with full extended surround format decoding for less than $200 if you're not expecting very good sound quality.
The amplification provided by today's receivers is also an astounding feat of electronics engineering. Many high quality receivers today pack 5 to 8 discreet amplifiers into one box. There is a limit to how small you can make an amplifier- the basic job can be performed by a microchip smaller than the eye can see. But because an amplifier will be required to dissipate large quantities of heat there is a limit to how small you can make them. Better amplifiers will be heavy with heat syncs prepared to dissipate wasted heat energy. Also the power supply on a receiver will be required to draw untold quantities of current to facilitate this energy used to power all your speakers for a loud soundtrack. This means the power supply must be made solidly with a capacity for high current at all times.
The receiver's processing might be simple enough to do in a tiny box and switching duties of the pre-amp can be performed with just enough space for the various plugs required to connect to its back. But it's in the amplification that creates the real weight of the receiver. A good quality receiver should be built with solid construction and should weigh more than just about any other component in your system. To heft a receiver in your hands you should immediately feel which side the plug is on by the weight of the power supply circuit and the solid heavy duty isolation transformer. Just getting a feel for the weight and solid construction of a receiver will tell you more about the unit than many of its published specifications.