A digital audio output sends sound from a source device to a receiver as digital data. It describes what travels over the link, not one specific plug. HDMI and S/PDIF are the common consumer paths, and S/PDIF is usually carried over either an optical (TOSLINK) or a coaxial connector. Whether a connection can carry a particular format is a separate question, and the answer depends on both the sending device and the receiving device.
What “digital audio output” means
The term describes audio sent as digital data from a source, such as a TV, Blu-ray player, computer, or game console, to compatible equipment such as a soundbar, AV receiver, or home theater system. Philips Support describes this use case directly: digital outputs send the signal to external home theater, soundbar, or AV receiver equipment. A digital output is not normally a speaker-level output and is not designed to drive passive speakers directly.
As an Amazon Associate I earn from qualifying purchases.
Two questions are easy to blur together. The first is the physical connection: HDMI, optical, or coaxial. The second is the signal format: uncompressed PCM/LPCM audio, or a compressed bitstream that a receiver decodes. A single output can use one connector while carrying either format, and the two are controlled and limited by different parts of the chain.
Common digital audio output connectors
The table below compares the three connection types that consumers most often encounter. Where a cited source does not state a limit, the cell says so instead of guessing.
#1 Best Overall
- Optical digital audio cable: Perfect for equipment with a TOSLINK interface (OPT In / OPT Out or S/PDIF In / S/PDIF Out). TOSLINK connector to TOSLINK connector (F05 connector)
- Versatile: Ideal for transmitting crystal-clear digital audio from your TV, video game console (PS3/PS4/Xbox One), DVD/Blu-ray player, or TV streaming box to a soundbar, amplifier/amp, stereo/Hi-Fi system, D/A converter, and more
- High-End: This metal-free fiber optic audio cable, featuring a fully flexible PVC jacket, is entirely immune to electrical interference. Each cable undergoes multi-stage testing during manufacturing to ensure maximum product quality and durability
- 24K gold-plated connectors: Corrosion resistant gold plating keeps connectors clean. And because these cables are fiber optic, they provide 100 % signal transmission with 0 % loss
- No risk: 36 months manufacturer warranty
| Connector | Labels you may see | Cable needed | Format notes | Channel or maximum format limit |
|---|---|---|---|---|
| HDMI | HDMI | HDMI cable | Microsoft’s Windows Dolby decoder documentation lists Dolby Digital Plus formatted for HDMI as a software output type. That listing does not show that every HDMI device supports it. | Not stated in the cited sources |
| Optical S/PDIF | Optical, TOSLINK, digital audio, optical audio | TOSLINK optical cable | Philips Support states that optical and coaxial digital connections both use S/PDIF format to transmit digital audio information. | Not stated in the cited sources |
| Coaxial S/PDIF | Digital coaxial, S/PDIF | Coaxial cable | Same S/PDIF format as optical. Microsoft’s Windows Dolby decoder documentation lists Dolby AC-3 formatted for S/PDIF as a software output type. | Not stated in the cited sources |
Labels vary by manufacturer and model, so the printed label on the back of a device is more reliable than a marketing name.
Two signal modes: PCM/LPCM and bitstream
Once a connection is chosen, the source’s output setting determines what is sent over it. The two modes work very differently.
Rank #2
- Please REMOVE the end protective caps before using the cable.
- IN THE BOX: 6-foot digital optical audio Toslink cable.
- CLEAR AUDIO: Multi-channel, fiber-optic digital audio output; corrosion resistant gold-plated connectors and buffer tubing for optimal signal transfer.
- DURABLE: Lightweight, flexible cable with a rugged PVC exterior and removable rubber tips that protect the cable when not plugged in; remove before using.
- CONNECTS DEVICES: Quickly connects a sound bar, CD player, Blu-Ray player, game console, or other device to an audio system or TV.
| Mode | Where decoding happens | What the link carries | What the receiver must do |
|---|---|---|---|
| PCM/LPCM | In the source device | Uncompressed audio that the source has already decoded | Convert the digital audio to sound. No decoding of a compressed format is needed. |
| Bitstream (pass-through) | In the receiver or external audio system | The encoded stream, forwarded unchanged by the source | Decode the stream. A receiver without support for that format cannot play it. |
Why the setting matters
Philips’ audio-format guidance, published 2017-03-01, uses Dolby TrueHD as an example. In PCM/LPCM mode, the player decodes the soundtrack and sends the resulting uncompressed audio. In bitstream mode, the encoded audio goes to the receiver, which decodes it. The same guidance notes that a device’s capabilities can force it to decode and send PCM even when bitstream output is selected. Treat this as a description of that player’s documented behavior, because options differ between products.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Pass-through does not mean the connection decodes sound
A link that carries a non-PCM stream does not decode anything itself. Microsoft Learn’s article “S/PDIF Pass-Through Transmission of Non-PCM Streams” (dated 2021-12-14) states: “The Sony/Philips digital interface (S/PDIF) format is defined primarily for transmitting PCM audio data, but it can easily be adapted to transmit non-PCM data.” The receiver performs the decoding when it supports the format. GStreamer’s documentation on digital audio pass-through describes the same arrangement, where the external audio system decodes the stream.
Rank #3
- Optical digital audio cable: Perfect for equipment with a TOSLINK interface (OPT In / OPT Out or S/PDIF In / S/PDIF Out). TOSLINK connector to TOSLINK connector (F05 connector)
- Versatile: Ideal for transmitting crystal-clear digital audio from your TV, video game console (PS3/PS4/Xbox One), DVD/Blu-ray player, or TV streaming box to a soundbar, amplifier/amp, stereo/Hi-Fi system, D/A converter, and more
- High-End: This metal-free fiber optic audio cable, featuring a fully flexible PVC jacket, is entirely immune to electrical interference. Each cable undergoes multi-stage testing during manufacturing to ensure maximum product quality and durability
- 24K gold-plated connectors: Corrosion resistant gold plating keeps connectors clean. And because these cables are fiber optic, they provide 100 % signal transmission with 0 % loss
- No risk: 36 months manufacturer warranty
Windows output types
Microsoft’s Windows Dolby decoder documentation lists PCM output types alongside Dolby AC-3 for S/PDIF and Dolby Digital Plus for HDMI. These are software output types on Windows. They are not a guarantee that every S/PDIF or HDMI device accepts every listed format.
Connection and format are separate checks
When sound is missing or wrong, confirm each part of the chain in this order:
Rank #4
- Optical digital audio cable: Perfect for equipment with a TOSLINK interface (OPT In / OPT Out or S/PDIF In / S/PDIF Out). TOSLINK connector to TOSLINK connector (F05 connector)
- Versatile: Ideal for transmitting crystal-clear digital audio from your TV, video game console (PS3/PS4/Xbox One), DVD/Blu-ray player, or TV streaming box to a soundbar, amplifier/amp, stereo/Hi-Fi system, D/A converter, and more
- High-End: This metal-free fiber optic audio cable, featuring a fully flexible PVC jacket, is entirely immune to electrical interference. Each cable undergoes multi-stage testing during manufacturing to ensure maximum product quality and durability
- 24K gold-plated connectors: Corrosion resistant gold plating keeps connectors clean. And because these cables are fiber optic, they provide 100 % signal transmission with 0 % loss
- No risk: 36 months manufacturer warranty
- Identify the digital output on the source and the matching input on the receiver, soundbar, or AV system. Use the printed labels, such as Optical, TOSLINK, Digital Coaxial, or HDMI.
- Confirm the cable or converter matches both ports (see the next section).
- Open the source’s audio output settings and note the selected format, either PCM/LPCM or bitstream.
- Check the receiver’s manual for the formats it accepts on that input. A format the receiver cannot decode will not produce sound.
- Repeat the test with the other format if the source allows it. If the source forces PCM, the receiver is not required to decode a compressed format.
Cables, converters, and mismatches
A cable only connects compatible ports. It does not change the signal format. A converter changes the connector or the signal medium so two ports can meet, but it does not decode compressed audio. Decoding happens in the source or the receiver, and digital-to-analog conversion happens in a DAC or in the receiving equipment.
Recommended Free Tools
- Optical to optical: a TOSLINK optical cable is the simple case.
- Optical source, coaxial input (or the reverse): an optical-to-coaxial or coaxial-to-optical converter may be appropriate. Confirm the direction and that the receiver accepts the format being sent.
- Digital output, analog-only receiver: Philips describes using a digital-to-analog converter. Confirm the input direction and supported formats before buying one.
Does optical or coaxial sound better?
Neither connection is inherently better sounding. Philips Support states that for the use case it describes, the digital information is identical. Practical differences come down to whether both devices support the chosen format and whether the port is implemented correctly on each device.
HDMI audio and a TV’s S/PDIF output are separate paths
A TV can receive audio over HDMI and also have its own S/PDIF output. A Philips support example reports that, on specified models, a protected HDMI-connected source may not produce digital audio at the TV’s S/PDIF connector. This is model-specific guidance, not a universal HDMI rule. Check the TV manual and its audio settings before assuming the S/PDIF port will carry the same audio as HDMI.
Sources referenced
- Philips Support, “How do I output sound from my Philips TV to external audio devices such as Home Theaters, Soundbars, AV Receivers, etc.?”
- Philips audio-format guidance, published 2017-03-01
- Microsoft Learn, “S/PDIF Pass-Through Transmission of Non-PCM Streams,” dated 2021-12-14
- Microsoft Learn, Windows Dolby decoder documentation
- GStreamer documentation on digital audio pass-through
Settings, menu names, and supported formats change between product generations, so confirm them in the manuals for both the source and the receiver.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Free tools Windows power users keep installed
One-click scans. No signup required.
