Summary
When using Tidal Connect (vtcs) on Volumio with an Allo Piano DAC + Kali reclocker, Hi-Res tracks (e.g. 24-bit / 44.1 kHz, 24-bit / 96 kHz) produce constant white noise / static, while 16-bit / 44.1 kHz tracks play correctly.
The same Hi-Res tracks play correctly when using Tidal integrated inside Volumio (MPD pipeline).
The issue is reproducible on both Raspberry Pi 3B and Raspberry Pi 4B, ruling out hardware limitations.
Environment
-
Volumio version: 4.119
-
Devices tested:
- Raspberry Pi 3B
- Raspberry Pi 4B (2GB)
-
DAC: Allo Piano DAC (PCM512x-based) + Allo Kali reclocker (GPIO I2S)
-
Output mode: I2S DAC enabled in Volumio
-
DAC driver:
dtoverlay=allo-piano-dac-plus-pcm512x-audio
Problem description
Works correctly:
-
Tidal Connect playback at:
- 16-bit / 44.1 kHz (S16_LE)
-
Volumio Tidal plugin (web UI) playback:
- 24-bit / 96 kHz (S24_LE)
- 24-bit / 44.1 kHz (S24_LE)
- and any track I play from tidal
Fails (white noise / static):
-
Tidal Connect playback at:
- 24-bit / 44.1 kHz
- 24-bit / 96 kHz
ALSA observations
During playback via Tidal Connect:
16-bit track:
format: S16_LE
rate: 44100
channels: 2
Hi-Res track (24-bit):
format: S24_LE
rate: 96000
channels: 2
access: MMAP_INTERLEAVED
Despite correct ALSA parameters and successful PCM device opening, audio output is only noise.
CPU usage during issue
System load shows no saturation:
vtcs CPU usage ~10%
system idle ~70%+
load average ~0.01
Conclusion: not a performance issue
Reproduction steps
-
Install Volumio 4.119
-
Configure:
- Allo Piano DAC (PCM512x overlay)
- I2S DAC enabled
-
Enable Tidal Connect
-
Play:
- 16/44.1 track → OK
- 24/44.1 or 24/96 track → white noise
Same behavior on:
- Raspberry Pi 3B
- Raspberry Pi 4B
Comparison with Volumio Tidal plugin
When playing the same Hi-Res tracks via Volumio Tidal integration (MPD):
- Audio is perfect
- 24-bit / 96 kHz works correctly
- No noise
This strongly suggests the issue is specific to Tidal Connect (vtcs path).
Key observation
Tidal Connect (vtcs) opens ALSA device successfully:
PCM opened successfully
However:
- audio is corrupted only in 24-bit mode
- 16-bit playback is unaffected
- issue is independent of Raspberry Pi version
Hypothesis
Possible causes:
1. PCM format handling bug in vtcs
- Incorrect handling of S24_LE stream on PCM512x DACs
- Possible mismatch in packed/unpacked 24-bit samples
2. ALSA direct path mismatch
- Tidal Connect bypasses Volumio audio pipeline
- Direct ALSA access differs from MPD route
3. PCM512x / Allo DAC driver interaction
- DAC works correctly via MPD
- Fails only when stream is provided by vtcs
Hardware/Software exclusions
- Not Raspberry Pi performance related
- Not power supply related
- Not I2S wiring / hardware fault
- Not DAC failure (works perfectly with MPD)
- Not network issue
- Not sample rate limitation (96 kHz is accepted)
Conclusion
The issue appears to be a Tidal Connect (vtcs) compatibility problem with PCM512x-based DACs (Allo Piano) when handling 24-bit audio streams via ALSA direct output.
Request
Please verify:
- vtcs PCM format handling for S24_LE streams
- ALSA output path differences between MPD and Tidal Connect
- Known issues with PCM512x / Allo Piano DACs
Additional notes
This issue is:
- 100% reproducible
- independent of Raspberry Pi version
- strictly related to Tidal Connect playback path
–
Thanks
Matteo