As part of this week’s sound subsystem fixes ahead of today’s Linux 6.18-rc6 kernel release is adding some quirks for supporting the PureAudio Lotus DAC5 and other PureAudio audio hardware.
The PureAudio Lotus DAC5 is a high-end digital/analog audio converter. With USB audio quirks merged to Linux 6.18 this week, it and other PureAudio products should be working better on the mainline kernel. This commit explains:
“The PureAudio APA DAC and Lotus DAC5 series are USB Audio 2.0 Class devices that support native Direct Stream Digital (DSD) playback via specific vendor protocols.
Without these quirks, the devices may only function in standard PCM mode, or fail to correctly report their DSD format capabilities to the ALSA framework, preventing native DSD playback under Linux.
This commit adds new quirk entries for the mentioned DAC models based on their respective Vendor/Product IDs (VID:PID), for example: 0x16d0:0x0ab1 (APA DAC), 0x16d0:0xeca1 (DAC5 series), etc.
The quirk ensures correct DSD format handling by setting the required SNDRV_PCM_FMTBIT_DSD_U32_BE format bit and defining the DSD-specific Audio Class 2.0 (AC2.0) endpoint configurations. This allows the ALSA DSD API to correctly address the device for high-bitrate DSD streams, bypassing the need for DoP (DSD over PCM).
Test on APA DAC and Lotus DAC5 SE under Arch Linux.”
The PureAudio APA DAC and PureAudio Lotus DA5 / DAC5 SE / DAC5 Pro are the ones receiving the USB audio quirks.
The code was merged as part of this week’s sound fixes and also a number of HP laptop audio quirks merged too for upcoming products.
