External USB DAC instead of the onboard audio path
A USB DAC sidesteps the mainboard's mono AW8110 amplifier and the core module's own codec or PWM output; one owner reports it resampling to 44.1 kHz/16-bit.
What it takes
- Plug & play
- Purchase required
Difficulty 1 of 3 — easy.
Details
tokyovigilante's thread maps the built-in path: the DAC lives on the core module — an ES8388 codec on the A-06, PWM-derived audio on the Raspberry Pi cores — switched through a WAS4729 into an Awinic AW8110 3 W mono class-D amplifier for the speaker. Nobody there calls it audiophile. A USB DAC on the side port or an internal USB header bypasses all of it.
tiaocunha's report from Bookworm 6.12 is the only hands-on note: the external DAC runs fine, but 96 kHz/24-bit files were being output at 44.1 kHz/16-bit in Elisa and VLC, and the thread has no answer yet.
Links
Open at Forum threadRelated mods
Koha's proposed ES9039Q2M DAC card on the expansion slot's I²S: 3.5 mm and 4.4 mm balanced headphone outputs, line-in, OPA1612 amps, about $75 — still a design.
A CM5 needs the RP1 audio remapped to GPIO 12/13 (dtoverlay=audremap,pins_12_13) and the amplifier enable pin driven high; current images already do both.
Below roughly 15 % battery the CM5's speaker picks up boost-converter noise; beams' power_save=0 modprobe option or Rex's audio-disable package quiet it.
On a CM4 the speaker amplifier is switched on by the devterm-audio-patch package; if it goes quiet, reinstall the package or drive GPIO 523 high from rc.local.
The all-in-one expansion card: RTL-SDR, SX1262 LoRa, GNSS, RTC and a USB hub with internal USB-C; the adapter board adds USB 3.0 and Gigabit Ethernet.
The 2024 original: an RTL-SDR (R820T2), USB hub and real-time clock on one expansion card — the board that started the AIO line.