Is There an HDMI to Optical Adapter? What It Does and When You Need One

Yes, an HDMI to optical adapter exists — an active HDMI audio extractor that pulls audio from an HDMI signal and sends it out through an optical TOSLINK port.

A soundbar or receiver with only an optical input can still play audio from a game console, streaming box, or Blu-ray player that outputs nothing but HDMI. The adapter sits between the two, splitting the signal so video keeps flowing to the TV while audio travels down the optical cable.

It cannot be a plain cable. HDMI carries audio and video together as one digital stream, while optical needs the audio separated out first — a job that takes active electronics and, on most units, a USB power connection.

What an HDMI Audio Extractor Actually Does

An HDMI audio extractor splits one HDMI input into two outputs: video passthrough to your display and digital audio to your sound system. The typical signal path runs from the source into the extractor’s HDMI input, out of the extractor’s HDMI output to the TV, and from the optical output to the soundbar, receiver, or amplifier. Many models also include a 3.5-mm or left/right analog output for older powered speakers.

Some extractors handle ARC or eARC, which lets them receive audio sent back from a compatible TV — including sound from the TV’s own streaming apps. ARC support is model-specific, so check before buying. A few units can output optical audio from an HDMI source with no display attached at all, which suits a monitor with video but no speakers.

When You Need One, and When You Don’t

You need an extractor when your source has HDMI out but your audio device has optical in only, and the two cannot meet any other way. That covers a TV paired with an older optical-only soundbar where the TV lacks usable ARC, a monitor with HDMI video and no audio output feeding external speakers, or a console that must send video to a display and audio separately to an older receiver.

Skip it when both your TV and soundbar support compatible HDMI ARC or eARC, or when the source and audio device already share matching optical, coaxial, USB, or analog connections. In those setups the extractor adds a box and a power cable for nothing.

Passthrough specs matter as much as the audio side. A 1080p extractor like the StarTech model passes video up to 1920 × 1080 at 60 Hz over HDMI 1.3b and will not preserve a 4K signal. Marketplace units advertise HDMI 2.1 passthrough up to 8K at 60 Hz and 4K at 120 Hz, but their optical output is often limited to PCM 2.0 or compressed Dolby or DTS 5.1 even when the HDMI passthrough handles far higher-bandwidth formats.

Optical bandwidth is the hard ceiling on any of these — it carries PCM stereo and compressed Dolby Digital or DTS 5.1, not the lossless formats that eARC can pass. If you want a shortlist of units that handle that limit well, this roundup of the best HDMI to optical adapters covers tested picks.

Setup Steps and Common Mistakes

Wiring the extractor takes about five minutes once you have the right cables in hand. Work through the order below and set your audio format last, since that step is where most failed setups go wrong.

1. Connect the HDMI source to the extractor’s HDMI IN port.
2. Connect the extractor’s HDMI OUT to the TV or monitor.
3. Run a TOSLINK optical cable from the extractor’s optical output to the soundbar, receiver, or amplifier.
4. Plug in the extractor’s USB or supplied power adapter — the StarTech design requires USB power to work at all.
5. Set the extractor’s audio mode switch to PCM, 2.0, 5.1, or ARC if it offers those options.
6. Set the source or TV audio output to a format your optical device supports.
7. Select the optical input on the soundbar or receiver and play something. Sound coming through the speakers while the TV picture stays normal means you’re done.

The mistakes repeat. People buy a passive HDMI-to-TOSLINK cable and wonder why nothing works — no such cable can extract audio. Others assume ARC works over any HDMI port, when it needs compatible ports, cabling, settings, and extractor support on both ends. Some see the “HDMI 2.1” label and expect Dolby Atmos through optical, which the optical bandwidth and codec support simply won’t carry. Leaving the extractor unpowered, using a weak USB port, or picking bitstream output when the receiver only handles PCM stereo also cause silence or garbled audio.

Small physical details matter too. Optical connectors are keyed and must be inserted the right way up, the protective caps come off before insertion, and the cable should not be bent sharply. HDCP version, HDR support, refresh rate, and VRR passthrough all depend on the exact combination of source, display, extractor, and audio device — not just the shape of the HDMI connector. The Marantz AV receiver documentation notes that HDMI and optical input assignments must be matched to the correct source before audio passes through.