USB and SPDIF DAC not switching sample rate

General
1

I’ve run across several old threads with the same issue. It seems that Coreelec has an issue where it does not signal sample rate changes to ALSA when using a usb dac. Instead, the sample rate remains at 48khz. I even tried setting a fixed sample rate, but the DAC never switches.

2

For completeness, I ran aplay --dump-hw-params -D hw:1,0 -f cd /dev/zero

HW Params of device "hw:1,0":
--------------------
ACCESS:  MMAP_INTERLEAVED RW_INTERLEAVED
FORMAT:  S32_LE SPECIAL
SUBFORMAT:  STD
SAMPLE_BITS: 32
FRAME_BITS: 64
CHANNELS: 2
RATE: [44100 768000]
PERIOD_TIME: [125 1486078)
PERIOD_SIZE: [8 65536]
PERIOD_BYTES: [64 524288]
PERIODS: [2 1024]
BUFFER_TIME: (20 2972155)
BUFFER_SIZE: [16 131072]
BUFFER_BYTES: [128 1048576]
TICK_TIME: ALL
--------------------
aplay: set_params:1387: Sample format non available
Available formats:
- S32_LE
- SPECIAL

I even tried using SPDIF output and it still does not switch sample rates under any circumstances.

3

It seems that PulseAudio does not recognize the correct sample rates:

2024-04-12 09:48:18.701 T:4127 info : Device 6
2024-04-12 09:48:18.701 T:4127 info : m_deviceName : @:CARD=EX5,DEV=0
2024-04-12 09:48:18.701 T:4127 info : m_displayName : EX5
2024-04-12 09:48:18.701 T:4127 info : m_displayNameExtra: Analog
2024-04-12 09:48:18.701 T:4127 info : m_deviceType : AE_DEVTYPE_PCM
2024-04-12 09:48:18.701 T:4127 info : m_channels : FL, FR
2024-04-12 09:48:18.701 T:4127 info : m_sampleRates : 48000
2024-04-12 09:48:18.701 T:4127 info : m_dataFormats : AE_FMT_S32NE
2024-04-12 09:48:18.701 T:4127 info : m_streamTypes : No passthrough capabilities

Does anyone know how to manually m_sampleRates?

4

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6

Confirming this is still present on the latest build. Details:

  • CE version: 21.3-Omega_p3i_T4b_20260704001258 (Amlogic-ng.arm, p3i fork)
  • Device: Ugoos AM6B+ (S922X-J), dt-id g12b_s922x_ugoos_am6b
  • DAC/DDC: Singxer SU-2 (XMOS XU208, USB Audio 2.0 G2) — recognized cleanly via lsusb / /proc/asound/cards, no driver quirks needed, registers as ALSA card 1.

Audio settings: Allow Passthrough Off, Number of channels 2.0, Stereo upmix Off, Resample quality High, Output device = the SU-2’s ALSA device.

Skin: default Estuary, unchanged. Confirmed T4b is still the current latest p3i release (no newer tag as of this post) — p3i doesn’t publish a separate nightly channel, it’s tag-based releases only.

Reproduction: played FLAC test files at 44.1/48/88.2/96/176.4/192kHz (from 24bit96.com’s test files) in a loop via Kodi. While each was playing, polled the live negotiated hardware params every 61s:

while true; do echo “=== $(date) ===”; cat /proc/asound/card1/pcm0p/sub0/hw_params 2>/dev/null || echo “(no active stream)”; sleep 61; done

Every single file — including exact 48kHz-family multiples like 96kHz and 192kHz, not just 44.1kHz-family rates — reported back:

rate: 48000 (48000/1)

So it’s not just a “44.1kHz doesn’t downsample cleanly” issue, it’s a flat lock at 48000 regardless of source, matching Astrotrain’s original finding exactly (this is distinct from the narrower “44.1kHz cutout” fix mentioned in a recent changelog, which wouldn’t explain 96k/192k also flattening to 48000).

Full output, polled every 61s while looping through the test files:

=== Tue Jul 14 19:25:47 UTC 2026 ===

access: MMAP_INTERLEAVED

format: S32_LE

subformat: STD

channels: 2

rate: 48000 (48000/1)

period_size: 1024

buffer_size: 16384

=== Tue Jul 14 19:26:48 UTC 2026 ===

[… same rate: 48000 repeats every 61s from 19:25:47 through 19:33:55 UTC, 9 polls total,

spanning the full 44.1/48/88.2/96/176.4/192kHz loop — see attached full log …]

Debug log: https://paste.coreelec.org/DatingEngraved

Happy to test anything or run further diagnostics if useful.

7

Wrong forum?

CE fork doesn’t fix that?

8

you’re on the wrong forum, this forum is for official CoreELEC releases
you’re on an EOL version, 21.3 is no longer maintained

read the blue box at the top of the forum

Before posting an error:

9

Sorry for that…

I’ll try to re-run with standard CoreELEC v22 nightly this weekend…

10

You might be using “Singxer USB Audio 2.0 G2 Analog” in Audio settings / Audio output device, it only has a single 48kHz.

Try using “Singxer USB Audio 2.0 G2 S/PDIF“ in Audio settings / Audio output device.

It will not have a setting for choosing the number of channels. But you will be able to set maximum frequency, set it to 192kHz.

11

That was it, thanks!

I had “ALSA: Singxer USB Audio 2.0 G2, Analog” selected as the output device — switching to the S/PDIF entry, plus raising “Limit sampling rate (kHz)” to 192.0, gives exact native-rate output at every rate I tested:

44100 → 44100/1
48000 → 48000/1
88200 → 88200/1
96000 → 96000/1
176400 → 176400/1
192000 → 192000/1

So this wasn’t the PulseAudio bug from the old thread after all — the Analog subdevice on this DAC is just hardware-limited to 48kHz, and I was pointed at it by mistake. Sorry for the noise, and thanks for the quick fix. Leaving this here in case anyone else searching this thread hits the same thing.