Usually, no: you cannot turn a TV's optical digital out into a working USB audio input with a passive cable. USB audio needs a host-peripheral relationship, and many speaker USB ports are meant for charging, updates, or file access rather than live external audio.
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Why a simple optical-to-USB cable usually fails
The Android Open Source Project's USB digital audio overview explains that USB has a single initiator called the host, which handles enumeration and data transfer. That is the key problem: a TV's optical output is just sending S/PDIF audio, while a random USB port is not automatically a compatible audio receiver. On the TV side, Sony's optical audio support article also makes clear that the optical jack is meant to output digital audio such as PCM or Dolby Digital to a device that can decode it.
Check what the USB port actually does first
| Port you have | Will optical-to-USB work? | Why |
|---|---|---|
| USB port on a speaker or soundbar used for service or updates | No | Bose says some speaker USB ports are for updates or setup only and provide no audio playback through that connector. |
| USB port on a computer, tablet, or phone acting as USB host | Sometimes | It can work only if the receiving device is a real USB audio interface or converter that the host can enumerate. |
| Optical input on a receiver or soundbar | Yes, and it is usually the easiest path | The TV is already designed to send digital audio over optical to compatible audio gear. |
| AUX or RCA input on speakers | Not through USB | You need a DAC with optical input and analog output instead. |
When optical-to-USB can work
Optical-to-USB can work when a real USB audio interface sits in the middle and a host computer is part of the chain. For example, the Sound Devices USBPre 2 is described as a USB audio interface with optical S/PDIF I/O for Mac and Windows computers. That is a very different setup from plugging a cable straight into a speaker's USB port.
When optical-to-analog is the right move instead
If your target device only has AUX, RCA, or another analog input, you do not want USB at all. You want a DAC that accepts optical input and outputs analog stereo. The official FiiO D3 (D03K) page is a good example of the device category: it converts optical or coaxial digital audio to analog stereo output. For this kind of setup, that is the correct bridge.
Why many speaker USB ports are the wrong destination
Many audio products expose USB for maintenance, not playback. Bose's rear-input guide for the SoundTouch 20 says its USB-A port is for updates by USB drive and offers no audio playback through that connector. JBL support similarly publishes examples where a soundbar USB port is described as service-only. If your product manual uses that kind of wording, no converter cable will fix it.
TV settings that often decide whether you hear anything
Even with the right hardware, TV settings matter. Sony's support guidance says optical output may need to be enabled and that incompatible audio systems may require the TV's digital audio output to be set to PCM. That also matters with PCM-only DACs such as the FiiO D3.
Listings to skip
- Skip passive cables that promise to turn Toslink directly into USB audio with no powered converter or host device.
- Skip adapters that do not say whether they act as a USB audio device or what side is the host.
- Skip converters that hide supported formats. If your TV is sending Dolby Digital and the DAC only accepts PCM, you may get silence.
- Skip any solution that assumes every USB port on a speaker is an audio input. Official support pages repeatedly show that many are not.
Bottom line: convert to the input your destination actually understands
If your destination has optical in, use optical directly. If it only has AUX or RCA, use an optical DAC that outputs analog. If you really need USB, add a true USB audio interface and a host computer or host-capable device that can enumerate it. What almost never works is the simplest-looking option: an optical-to-USB cable plugged into a generic USB port.