Uncompressed Multichannel Playback via AVR

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1

Hi Community,

OK, I’m new to Volumio, so pls. excuse me in case that question has been asked already a Million times before - but at least googling didn’t help …
I installed Volumio on a Raspberry Pi 5 and conncted it it via an HDMI cable to my Denon AVR-A1H.
That generally worked, but it didn’t sound good.
So I hooked up a DDC to the Raspi via USB and used a Toslink cable to connect to the Receiver.
Now sound is impressive for “standard” audio, I.e. 2-channel 44,1/48 kHz.
But here comes the catch - I have a lot of ripped SACDs (I use my hacked PS3 to rip my SACDs), DVD-As, BD-As and multichannel high-res audio files sitting on my Synology NAS that I’d love to stream to my AVR - but my USB-DDC only supports 2-channel PCM.
Furthermore audio via the Raspi HDMI seems to be crap anyway (at least when you use the original Raspi OS).
So my question is - does something like a USB-to-HDMI-DDC exists, that prsents itself as a DAC via USB and announces that it supports multichannel high-def bitstream (LPCM, Dolby Atmos, DTS:X, DTS-MA, Flac, etc.) and feeds that
via HDMI to the AVR - or should I rather use a PC as the Volumio plattform of choice and connect that directly via HDMI 2.1 to the AVR?
Happily receiving any input!
Cheers
Stefan

2

I am also comtemplating hooking up a Pi4 Volumio to a soundbar via hdmi for audio playback. I wouldn’t mind if the hdmi output has to mirror my hdmi touchscreen attached currently. A few posts I’ve seen are from a few years ago.

3

Hey @stefvienna,

Welcome to the community, and thanks for the detailed description of what you are trying to achieve.

Here are the facts as they stand today with Volumio and Raspberry Pi:

  • HDMI on Raspberry Pi can technically carry multichannel LPCM, but it has limitations. The Raspberry Pi firmware and drivers prioritize video use cases, and for pure audio playback it is often not bit-perfect, especially for higher resolutions or DSD. Many users report degraded quality or unreliable multichannel playback over HDMI.
  • USB audio on Raspberry Pi is very solid, but most USB DACs (and USB DDCs like the one you mentioned) only expose 2-channel PCM. Multichannel DACs do exist, but they are rare, expensive, and mostly geared towards pro-audio rather than consumer AVRs.
  • What you are describing (a “USB-to-HDMI DDC” that appears to the Pi as a DAC and then outputs bitstream over HDMI to an AVR) unfortunately does not exist as a plug-and-play device. HDMI audio extraction is normally the other way around (HDMI to Toslink/Coax), not USB to HDMI with multichannel bitstream.
  • For formats like SACD ISOs (DSD), DVD-A or Blu-ray Audio rips, the Pi will typically need to transcode to PCM. Native bitstreaming (Dolby TrueHD, DTS-MA, Atmos) is not supported in Linux audio stacks without passthrough through something like Kodi. Volumio is built on ALSA and MPD, which focus on high-quality PCM and DSD over USB, not HDMI bitstream formats.

So to answer your question:

  • If your main goal is multichannel high-res and surround formats into your Denon AVR, a PC platform (NUC, small Intel box, etc.) with proper HDMI 2.1 and Linux driver support is the more realistic choice. That way, the AVR receives bit-perfect LPCM multichannel over HDMI.
  • If you are happy with 2-channel audiophile playback, then the Pi plus a good USB DAC/DDC is still the best low-power solution.

To my knowledge - there is unfortunately no “magic USB-to-HDMI bridge” that does what you want today.

Call to the community members to chime in to confirm, contradict, or add their own experience so we can clarify this together.

Kind Regards,

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4

There was another post stating that they had success a few years back with no details. Personally, I understand that HDMI audio is likely not a priority for development. I’m just looking to even try 2 channel bit perfect output thru HDMI [not i2s audio thru hdmi].

These are the limitations I’m weary of by way of chatgpt:

Limitations & considerations

  • One active output: Volumio cannot output to two different sinks simultaneously (e.g., DAC + HDMI).
  • CEC / passthrough: Some soundbars expect CEC handshakes; make sure your HDMI cable supports audio return (ARC/eARC not supported on Pi).

This is the config it also suggested:

# Keep both HDMI outputs active
hdmi_force_hotplug=1

# Touchscreen on HDMI0 (closest to USB-C power)
# Leave this as default video; Volumio GUI runs here

# Soundbar on HDMI1 (second micro-HDMI)
# Force audio to this port
hdmi_drive:1=2
hdmi_force_hotplug:1=1
5

Many thanx for the detailed answer!
So I’ll get a Mini-PC and will give Volumio a try there.

6

OK, so I grabbed an Asus Pn43 miniPC and installed Volumio there.
I had to jump over some hurdles in BIOS to get it installed (disable Secure Boot and TrustedPlatform) and working (enable HD Audio).
But I can confirm that it’s playing multichannel audio over HDMI now.
Current test is a 5.1 flach with 88.2 kHz, 24 bits.
My Denon A1H Shows Multi Ch Input on the display and the status Info confirm that.
Using the TV screen for navigation is also a bonus to me, since the Rasparry Pi only presented a Text console with login prompt, although I would assume that could be changed.
So far I’m happy now.
I also hooked up the USB2Toslink-DDC and will switch back and forth between HDMI and DDC to see weather the quality of sound changes and will report back here next week.
Cheers, Stefan

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