Denon and Marantz HEOS U40 Update Fixes Qobuz Connect, TuneIn, Power-On Volume and HDMI Pop Noise

Denon has documented a substantial U40 software release for HEOS-built-in Denon and Marantz products. The staged firmware rollout ran from 22 July to 6 August 2026, while HEOS app version 3.139.250 arrived on 5 August. The update combines expanded web-interface controls with officially confirmed fixes affecting streaming, saved controls, volume behaviour, HDMI output and two-channel bass management.

Verification: Official. Denon’s version history confirms the firmware branches and listed fixes. Owners should still verify the exact product group before comparing version numbers.

Applicable products, versions and dates

Denon separates products into two firmware groups. The higher number is not automatically the correct target for every Denon or Marantz product, and owners should use the normal update path for their exact device rather than trying to force another group’s firmware.

What changed

For products with the supported HD web interface, U40 adds an Option Menu, Info Screen, Virtual Remote and a direct link to the owner’s manual. HEOS app 3.139.250 also improves in-room group management.

The official release notes confirm fixes for:

• TuneIn stations repeating short sections of audio.
• Qobuz Connect playback stopping partway through.
• Qobuz Connect connection failures that prevented playback.
• Unknown-error messages during Qobuz playback.
• An AVR restoring the last volume after reconnecting to the HEOS app even when a fixed Power-on Level was configured.
• Incorrect sampling-rate information in AVR Remote after switching away from DSD playback in HEOS Music.
• Quick Select failing to store or recall Spotify.
• A speaker pop when the HDMI output refresh rate changed.
• Two-channel crossover-frequency adjustments in the web interface having no effect.
• Unwanted subwoofer output when two-channel speakers were set to Full Range and Sub Output was set to LFE.
• A Room View speaker icon that did not match the actual manual two-channel playback setting.

Why this matters

The most consequential items are the Qobuz Connect and HDMI fixes. Interrupted or failed Qobuz playback can make a network receiver unreliable for daily streaming, while an HDMI-related pop can be alarming when an AVR is connected to a television or display. The fixed power-on-volume behaviour also matters for users who depend on a predictable startup level.

U40 strengthens the case for updating supported products, but the release notes do not prove that every similar Qobuz, grouping, HDMI or bass-management complaint has been eliminated on every model. Denon groups devices in the public history rather than attaching every fix to an exhaustive model-by-model list.

How to update

1. Use the receiver or player’s normal network-update function.
2. Update the HEOS app through the official app store for the phone or tablet.
3. Keep the product connected to stable power and network service until installation is complete.
4. After updating, confirm the installed firmware and app versions on the exact product.
5. If a previously observed problem remains, record the model, firmware branch, app version, input path and reproduction steps before contacting support.

Because the rollout was staged and two firmware branches are documented, do not install files intended for a different product group.

Risks and verification notes

• Official status: Confirmed by Denon’s published software version history and corroborated for the app version through Apple’s App Store.
• Rollout: Staged; timing depended on product and region.
• Model scope: The public history groups devices rather than listing every supported model beside every fix.
• Product Issues status: SoundPath Lab has not marked an existing issue as resolved because the public registry contains no precise matching issue ID. A manufacturer fix claim would remain resolved-pending-verification until supported by independent retesting or two independent owner confirmations.

Sources

• Denon HEOS app and firmware version history
• HEOS on the Apple App Store

Related: Firmware & App Update Tracker · Product Issues & Limitations

Disclosure and revision note

SoundPath Lab has no asserted manufacturer sponsorship or affiliate relationship for this software-update report. No purchasing links are included.

Updated 20 August 2026: Initial publication based on Denon’s official U40 version history and the HEOS App Store record. No existing Product Issues status was changed.

Feature image: neutral editorial illustration created for SoundPath Lab. It is not an official Denon, Marantz or HEOS product image and contains no brand marks.