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Cambridge Audio CXA81 Mk II: check a silent optical TV source with stereo PCM

Cambridge Audio CXA81 Mk II — check a silent optical TV source with stereo PCM. Follow the exact documented route and keep the actual result.

Manufacturer-documented Reviewed 2026-11-09 · Revision 1

Follow these checks in Audio Fix →

When this guide applies

Exact Cambridge Audio CXA81 Mk II. Verified TV optical output cable and correct downstream bank; no HDMI ARC compatibility assumed. Only normal external user controls; no mains modification, chassis opening, reset or firmware installation.

Connection scope: Optical digital audio. Symptom: There is no playback sound.

This is a documented check, not a diagnosis of your equipment. The model name does not confirm the selected input, mode, software or connected partner.

If your exact model or a required setting is unknown, use the “I don’t know” branch below. Do not apply a similarly named model’s instructions.

Checks and possible outcomes

Start at scope. Follow the link that matches what you actually observe. Alternative branches are not a single sequence of actions.

scope

Confirm the exact setup

The TV-to-optical-input cable and downstream speaker route are confirmed, you know the TV’s actual format menu and accept changing that source format.

Look for: Choose only a detail you can confirm.

  • Manufacturer-documented Cambridge Audio CXA81 Mk II official manual ↗Getting connected — Connecting a TV — The digital inputs decode stereo PCM, not Dolby/surround. The TV must output PCM/stereo and the matching D1/D2/D3 input must be selected. Optical supports 16/24-bit 32–96 kHz.Exact CXA81 Mk II sections of the explicitly shared Cambridge manual. A sibling model’s exclusive control or firmware prerequisite is not assumed. · Source checked 2026-11-09

a1

Inspect the TV digital output format

Use the actual TV manual rather than an assumed menu label.

Look for: Perform this one check and observe the actual response.

  • Manufacturer-documented Cambridge Audio CXA81 Mk II official manual ↗Getting connected — Connecting a TV — The digital inputs decode stereo PCM, not Dolby/surround. The TV must output PCM/stereo and the matching D1/D2/D3 input must be selected. Optical supports 16/24-bit 32–96 kHz.Exact CXA81 Mk II sections of the explicitly shared Cambridge manual. A sibling model’s exclusive control or firmware prerequisite is not assumed. · Source checked 2026-11-09

a2

Choose compatible stereo PCM

Do not send a Dolby or surround bitstream to this stereo DAC.

Look for: Perform this one check and observe the actual response.

  • Manufacturer-documented Cambridge Audio CXA81 Mk II official manual ↗Getting connected — Connecting a TV — The digital inputs decode stereo PCM, not Dolby/surround. The TV must output PCM/stereo and the matching D1/D2/D3 input must be selected. Optical supports 16/24-bit 32–96 kHz.Exact CXA81 Mk II sections of the explicitly shared Cambridge manual. A sibling model’s exclusive control or firmware prerequisite is not assumed. · Source checked 2026-11-09

a3

Select the matching D1 or D2 optical input

Match the input label to the actual cable and compare a familiar passage at low level.

Look for: Perform this one check and observe the actual response.

  • Manufacturer-documented Cambridge Audio CXA81 Mk II official manual ↗Getting connected — Connecting a TV — The digital inputs decode stereo PCM, not Dolby/surround. The TV must output PCM/stereo and the matching D1/D2/D3 input must be selected. Optical supports 16/24-bit 32–96 kHz.Exact CXA81 Mk II sections of the explicitly shared Cambridge manual. A sibling model’s exclusive control or firmware prerequisite is not assumed. · Source checked 2026-11-09

result

Check the actual result

Does that compatible optical input now play?

Look for: Choose only a detail you can confirm.

  • Manufacturer-documented Cambridge Audio CXA81 Mk II official manual ↗Getting connected — Connecting a TV — The digital inputs decode stereo PCM, not Dolby/surround. The TV must output PCM/stereo and the matching D1/D2/D3 input must be selected. Optical supports 16/24-bit 32–96 kHz.Exact CXA81 Mk II sections of the explicitly shared Cambridge manual. A sibling model’s exclusive control or firmware prerequisite is not assumed. · Source checked 2026-11-09

Possible result

Confirm the unknown detail first

Do not infer a source setting, installed cartridge, connector role, software state or partner capability. Obtain the exact documentation before continuing.

insufficient data

Reaching this result does not mean the issue is solved. Only your own feedback can report improvement.

    Possible result

    Keep the actual observation for support

    Record the exact model, source, input and last observed response. These checks do not diagnose a failed component. No reset, service work or blind update is prescribed.

    next support

    Reaching this result does not mean the issue is solved. Only your own feedback can report improvement.

      Possible result

      Checks completed — keep the observed result

      This records the observation in this particular setup, not a guaranteed cure, physical Audio Review test or measurement.

      steps completed

      Reaching this result does not mean the issue is solved. Only your own feedback can report improvement.

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