In the previous post I mentioned plans to move beyond TAS5805M. That work is now far enough along to share - introducing the Louder Raspberry Hat “Plus” model



This is not a redesign of the concept but an evolution of the platform: more efficient hardware, more advanced DSP, and a linux driver that unifies support across DAC family

The Plus version is built around a newer TAS5825M DAC that I previously tested on ESP32 and now integrated into the Raspberry Pi HAT platform. The most immediate improvement is power efficiency. The new chip has significantly lower Rds(on), which reduces heat dissipation and improves behavior under high load. In practice, it runs noticeably cooler in the same enclosure and leaves more thermal margin for compact builds.



On the software side, I reworked the driver so both DAC families are supported by the same code. The system still presents a single sound card with independently controlled codecs for 2.0 and 2.1 Hats, but now the platform is not tied to one specific chip. Configuration model, DSP control, and runtime behavior remain consistent, you just need to specify the I2C right address (examples provided in the docs).

Another addition is fault monitoring exposed to user space through ALSA. Previously faults could be handled at driver level; now they are also observable directly from user space without custom tooling. This allows for example automatically back off volume when overtemp warning lit up.



Everything else from the original platform remains:

• Single or cascaded Dual DAC topology with independent DAC controls
• 15-band EQ adjustable on the fly and restored on boot
• LF filter for subwoofer channel with cutoff frequency and gain control
• Separate gain controls for L/R and Sub/Sat balance
• New fast connectors 😉

The Plus model is intended to extend the platform rather than replace the existing boards. Both versions will remain supported by the same driver stack. Both generations are available on Tindie

Glad to hear your thoughts!