Most A/V receivers include ample audio inputs (both digital and analog). Audio inputs on an A/V receiver let you connect the audio outputs of DVD players, CD players, game consoles, HDTV tuners, Media Center PCs, digital audio players for MP3 and other computer audio, and many newer digital cable set-top boxes or DSS satellite receivers. Price can be a factor: Inexpensive receivers may not offer enough of the right kind of audio inputs.
To use all your home theater components, ensure that you have enough inputs on the back of your receiver. Before you buy anything, think about the components you have and what you’ll soon be getting and make sure the receiver has enough of the right types of inputs to support them.
Digital audio inputs
Connecting audio sources by using digital inputs (instead of the traditional analog inputs) is a good idea because the digital signals are much less prone to electrical interference than analog signals. A more important consideration is that digital inputs are required to get digital surround-sound formats, such as Dolby Digital and DTS, into your receiver.
An exception to this rule involves devices (mainly DVD players) that have a built-in Dolby Digital or DTS surround-sound decoder. You can connect these to your receiver using analog audio connections, but this may not be the optimal solution for the following reasons:
You need to use six cables instead of one.
You may lose some signal quality due to interference in the analog signal.
You need a receiver that has the necessary six analog inputs on the back — and even if you have these, they may be “taken up” by the six channel outputs of a DVD-Audio or SACD player.
There are two types of digital audio connections: coaxial and optical. Some high-end audio folks believe that coaxial sounds better; it may have a slight sonic benefit, but not so much that regular people can tell.
This is another type of digital connection that can carry digital audio signals: the HDMI connection, which is increasingly used for HDTV tuners/satellite receivers and set-top boxes and which is also common in other devices such as DVD players (both regular DVD players and Blu-ray disc players) and even in game consoles such as the Xbox 360 and PlayStation 3. If you use HDMI to connect these devices to your home theater receiver, you don’t need to use a separate digital audio connection — the audio and video are both carried over the HDMI connection.
Analog audio inputs
Although digital connections are the way to go when they’re available, analog is just fine when it’s your only option. Devices that use analog audio connections include the following:
Older CD players (without a digital output)
External radio tuners
Analog VCRs
Cable set-top and DSS receivers without digital outputs
Cassette recorders
Older game consoles (such as Nintendo 64 and the original PlayStation)
The newest digital audio sources, SACD and DVD-A
All the devices in the preceding list — except for SACD and DVD-Audio — use a simple pair of analog audio connections, one for the left channel and one for the right. The inputs on the receiver are labeled, and these labels correspond to the buttons on the front of the console and on your remote control. It’s always nice if the names on the receiver’s inputs match input names on the device to which you’re connecting the receiver, but it’s not essential (other that phono inputs, which should be used only for a phonograph/record player).
For DVD-Audio and SACD players, you need a special set of analog inputs with six connectors. These formats can support multichannel audio (five channels plus a subwoofer for bass) and therefore need the extra inputs. Many newer receivers have a six-input section (called a 5.1 analog input), so you can use an SACD or DVD-A player.