What is a Digital Optical Connection?

All about this home theater system audio connection

What to Know

  • Digital audio connections use fiber optics and are found in some home theater systems and car stereos.
  • Devices that support digital optical connections include cable boxes, game consoles, Blu-ray players, and TVs.
  • Some multi-channel standards such as Dolby Atmos and DTS:X cannot use digital optical connections.

This article explains what digital optical connections are and lists types of equipment that support this standard.

What Is a Digital Optical Connection?

Digital optical is a type of audio connection in home theater systems and stereo systems for automobiles. Fewer devices are being made with digital optical output ports, so it's important to understand which types of connections your audio equipment can support.

Digital optical is a physical connection that uses fiber optics to transfer audio data from a compatible source device to a compatible playback device using a specially designed cable and connector. The audio data is converted from digitally encoded electrical pulses to light on the transmission end using an LED light bulb.

After the light passes through the digital optical cable to its destination, the light pulses convert back to electrical pulses containing the audio information. The electrical sound pulses then travel further through the compatible destination device (such as a home theater or stereo receiver) that processes them, eventually converting them to analog signals and amplifying them so that they can be heard through speakers or headphones.

Another name for digital optical connections is TOSLINK connections. TOSLINK is short for "Toshiba Link" since Toshiba was the first company to standardize the technology. The development and implementation of the digital optical (Toslink) connection paralleled the introduction of the CD audio format, where it was first used in high-end CD players before it expanded into home theaters.

Cables2Go Digital Optical Toslink Cable Example

Devices That Can Have Digital Optical Connections

Digital optical connections typically appear in the following devices:

  • DVD players
  • Blu-ray Disc players
  • Ultra HD Blu-ray Players
  • Media streamers
  • Cable/satellite boxes
  • DVRs
  • Game consoles
  • CD players
  • Home theater receivers
  • Soundbars
  • Vehicle stereo receivers
  • TVs

SomeBlu-ray players have eliminated digital optical as an audio connection, instead opting for an HDMI-only output for both audio and video. If you have a home theater receiver with digital optical connections but no HDMI connections, make sure the devices you want to use include a digital optical output connection.

Digital optical connections only transmit audio. For video, you need to use a separate type of connection, such as HDMI, component, or composite.

Digital Optical Connections and Audio Formats

The types of digital audio signals that can be transferred via a digital optical connection include two-channel stereo PCM, Dolby Digital/Dolby Digital EX, DTS Digital Surround, and DTS ES surround sound formats.

The digital optical connection was made to accommodate the digital audio standards of its time (mainly 2-channel CD playback). Thus, 5.1/7.1 multi-channel PCM, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, DTS:X, and Auro 3D Audio digital audio signals cannot be transferred via digital optical connections. These types of audio signal formats require the use of HDMI connections.

Digital Optical vs Digital Coaxial Connections

Digital coaxial is another digital audio connection option with the same specifications and limitations as digital optical. However, using RCA-style connectors instead of using light to transfer audio signals, data moves via traditional wire.

OPPO Digital BDP-103D – Digital Coaxial, Digital Optical

The major difference between coaxial and optical cables is that the former offers higher bandwidth. Coaxial connections are also more sturdy, but they are prone to electromagnetic interferences.

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