Receivers and amplifiers are the foundation of surround-sound home theater, audio-video (A/V) systems offering movies and music, and audio systems connected to a variety of music components. Receivers differ from amplifiers in configuration, but both drive audio signals to speaker systems.

What’s an Amplifier?

Amplifiers power speakers from a single-source audio component. They transform low-voltage signals into signals with enough gain to power speakers. Stereo power amplifiers normally transfer much more wattage per channel than receivers do, so they’re able to handle the needs of high-end speakers. Wattage isn’t the power of the volume that goes through each channel, but the amount of clean sound for any given ohm input. Speakers need not be “loud,” as much as they need to yield clear, powerful sound without distortion.

Stereo Receiver Amplifiers

A/V and stereo receivers offer multi-channel inputs for speakers, with built-in amplifiers to boost audio signals for output. Receivers may also offer one or two pre-amplifier outputs for subwoofers.

Surround-sound, home-theater receivers have at least five channels for front, right, and center speakers, and right- and left-surround speakers. Channels for rear center, right, and left and extra surround-sound speakers, and preamp outputs for subwoofers, can boost a 5-channel receiver’s designation up to 13.2, meaning 13 available channels and 2 subwoofer pre-amps. Receivers also offer outputs for home audio components, including TVs, turntables, CD players, external tuners, and set-top boxes.

Audio Capabilities of Multi-Channel Receivers

Surround-sound receivers driving output to five or more speakers immerse you into movies or music as they were originally recorded. You can also get the same separation of sound when using headphones and earphones.

Home-theater A/V receivers decode the audio signals that are recorded on different media, such as DVDs and Blu-ray discs. The formats include the Dolby Digital and DTS:X lines, each of which delivers reproductions of recorded audio for a specific number of receiver channels. Many receivers are equipped for more sophisticated audio signaling from formats such as Dolby Atmos for overhead speakers and the immersive surround sound of 3D audio being offered by Auro Technologies.

Receivers also come with multiple HDMI ports for transferring video formats on various media to TVs and monitors, including resolution from 1080p to 3D to 4K. Many can handle the most advanced video augmentation, including high-dynamic range (HDR) contrast boosting with Dolby Vision and HLG, 4:4:4 color saturation, and 21:9 ultrawide format.

Receivers for Internet, Wireless, and Multi-Room Sound

The vast majority of receivers offer Ethernet connectivity for music streaming and network sharing, and Wi-Fi router and Bluetooth connectivity for single and multi-room sound systems with wireless speakers. Many home-theater receivers can operate multiple A/V systems in other rooms, or—using different audio platforms, including HEOS and MusicCast—can send music from individual components to the wireless speakers.

Check out the vast array of stereo receivers and separate amplifiers at B&H Photo and discover which one is best suited to what you need in your home theater or audio-only system.