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Everything You Need to Know About the SPDIF Connection


The SPDIF Connection

There are two kinds of consumer-level SPDIF connections, coaxial and optical. The coaxial connection uses a mono RCA connector, usually painted orange, to make it easier to differentiate it from video connections that use a similar connector. The optical connection uses a square connector called Toslink (Toshiba Link). Some equipment has both connectors; some have only one of them. Let’s see some examples.

In Figure 6, we have the back of a professional-grade CD player (Pioneer CDJ-100S), which has a coaxial SPDIF output. Note how it has a switch for you to enable this output. The other connectors are the analog audio outputs and a jack for an optional remote control.

Coaxial SPDIFFigure 6: Example of a coaxial SPDIF output

In Figure 7, we see the back of a DVD player, which has both the optical and the coaxial SPDIF outputs.

Optical and Coaxial SPDIFFigure 7: Example of optical and coaxial SPDIF outputs

In Figure 8, we have the back of a video game console, which has an optical SPDIF output as well as an HDMI output.

Optical SPDIFFigure 8: Example of optical SPDIF output

In Figure 9, we have the back of an audio receiver, featuring an optical SPDIF input and a coaxial SPDIF input. See how, on this particular receiver, the optical SPDIF input is labeled “Video 2 In,” and the coaxial SPDIF input is labeled “DVD In.” This is important information because these are the names the equipment uses for these inputs.

Optical and Coaxial SPDIFFigure 9: Example of an optical and a coaxial SPDIF input on an audio receiver

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.