Multichannel Analog Audio Connections - What You Need To Know

There is still room for analog audio connectivity in the digital age

Example of Multi-Channel Analog Audio Inputs and Outputs
Example of Multi-Channel Analog Audio Inputs and Outputs. Images provided by Yamaha

Although the emphasis these days is on digital connectivity, home theater has a long tradition of analog audio starting from the days of Hi-Fidelity and stereo.

As a result of this foundation, even though most home theater components provide primarily digital connection options, (such as HDMI, digital optical, digital coaxial, and USB). There are lots of components in use, such as CD players, audio tape decks, VCRs, and older DVD and Blu-ray Disc players that provide either analog audio-only or digital and analog audio connectivity.

This state of affairs has resulted in many home theater receivers still providing some analog audio connection options. The most common type is analog stereo inputs/outputs, subwoofer, and Zone 2 preamp outputs, multichannel analog inputs and outputs are sometimes provided.

What Multichannel Analog Connections Are

Multichannel analog connections (whether for input or output) consist of a separate audio connection for each channel of audio. In other words, just as there are left and right channel analog audio connections for stereo, for certain surround sound applications, in addition, to the left and right analog stereo connections, it is possible to include separate analog audio connections for the center, left surround, right surround, and, in some cases also left surround back and right surround back. These connections utilize RCA jacks and cables.

Multichannel Preamp Outputs - Home Theater Receivers

The most common multichannel analog connection option, which is found mostly on mid-and-high end home theater receivers and AV preamp/processors, is what is referred to as multichannel analog audio preamp outputs.

What these outputs do is connect a home theater receiver or AV preamp/processor external amplifiers. This enables consumers to still access all of the audio and video processing features of a home theater receiver, but if onboard amplifiers are not powerful enough for a newer setup, the preamp outputs allow connection to more powerful external power amplifiers for one, more, or all available channels.

However, when multichannel analog preamp outputs are used, they disable a home theater receiver's internal amplifiers that are designated for the corresponding channels. In other words, you cannot combine the power output of an internal amplifier with an external amplifier for the same channel.

On the other hand, some home theater receivers allow you to reassign those internal amplifiers to other channels that are not being bypassed. this feature allows users to use a mix of internal and external amplifiers to expand the number of channels that a home theater receiver can control.

Read the instruction manual for your specific home theater receiver for any details as to whether the internal amplifier reassignment option is offered.

Multichannel Preamp Outputs - AV Processors

While multichannel analog preamp outputs are optional on home theater receivers, they are required on AV Preamp Processors.

The reason for this is that AV Preamp processors do not have the built-in amplifiers that are required to power speakers, so, in order to get audio signals to speakers, the analog preamp outputs enable connection to an external power amplifier(s) via analog audio preamp outputs. The amplifiers, in turn, are able to power the speakers.

Multichannel preamp outputs can also be found on either older DVD/Blu-ray disc players, but these days, are limited to a small number of high-end Blu-ray Disc players.

Multichannel Analog Preamp Outputs - DVD and Blu-ray Disc Players

Before the introduction of HDMI, some higher-end DVD players, and even a small number of Blu-ray Disc players offered (and a limited number still do) a multichannel analog preamp output option.

These connections provide(d) support(ed) two capabilities. The first is the ability for the player to decode Dolby Digital and DTS surround sound audio formats internally and then pass that decoded surround sound signal to an older home theater receiver that may not have its own built-in Dolby Digital/DTS decoding capability (in other words, no digital optical/coaxial, or HDMI inputs), but may provide a set of multichannel analog audio inputs. When this option is used, your home theater receiver will display either Direct or PCM on the front panel instead of Dolby or DTS. However, you are still getting the benefits of those formats as they were decoded before they reached the receiver.

The second ability is support for two audio formats that there were introduced in 1999/2000, SACD and DVD-Audio that affects audio connectivity, even if the home theater receiver has built-in Dolby/DTS decoding and provides digital optical/coaxial, and HDMI inputs.

Due to bandwidth requirements, the SACD and DVD-Audio formats cannot make use of digital optical or digital coaxial audio connections, which meant that (before HDMI) the only way to transfer those audio signals to a home theater receiver was via the multichannel analog audio connection option.

However, to use the multichannel analog preamp outputs on a DVD or Blu-ray Disc player that has them, you need to have a corresponding set of inputs on a home theater receiver or AV preamp/processor.

Multichannel Analog Inputs

Before HDMI arrived, multichannel analog audio input connections were once very common on home theater receivers, AV preamp/processors, but are rare these days.

However, if you do have a home theater receiver or AV processor that does offer this option, you have the flexibility to take advantage of a DVD, Blu-ray Disc player, or another source component that may offer this as an output connection option.

Keep in mind that multichannel analog inputs are discrete connections. This means if you are connecting a two channel stereo analog source, such as CD player, you need to only use the front left and right channel inputs, and for full 5.1 or 7.1 channel surround sound that you need to use all of the inputs and make sure you connect the corresponding designated channel outputs from your source component to the correctly designated channel inputs.

For example, if you connect the analog front left/right preamp outputs of your source device to the surround left/right analog inputs, the sound will come out of the surround speakers instead of the main left/right speakers. Also, it is very important the if your source component has a subwoofer preamp output that it should be connected to either a receiver's subwoofer preamp input, so it can be routed to the receiver's subwoofer output, or you can bypass that option and connect the subwoofer output from the source device directly to the subwoofer.

The Bottom Line - Be Aware Of Your Audio Connection Options

There are a lot of connection options in home theater, and through the years, new options have been introduced, such as HDMI, and old options are in the process of or have been eliminated and others have been consolidated, such as shared analog video inputs on newer TVs - but many consumers have a mixture of old and new components that need to be connected and use. The multichannel analog audio connection option is one choice that may be available to you if you need it.