Previously, we wrote about the Louder Raspberry Pi, an open-source media center that integrates the Louder Raspberry Hat based on a 25W TAS5805M Class-D amplifier. Now, the developer has introduced the Louder Raspberry Hat Plus, upgrading from the TAS5805M amplifier to the more powerful TAS5825M, capable of driving up to 53W in mono (PBTL) mode while offering improved efficiency and thermal performance.
The Louder Raspberry Hat Plus is compatible with all Raspberry Pi models and comes in 1X and 2X variants. The 1X version delivers up to 2×32W at 8Ω or 2×45W at 4Ω, the 2X version, on the other hand, supports 2×32W plus a dedicated 53W subwoofer channel, with bridge mode available for higher mono output.
The board also integrates a DSP with 15-band parametric EQ per channel, 128-tap FIR filtering, 3-band DRC, selectable LF/HF crossovers, digital volume and gain control (32-step analog gain), selectable modulation schemes, adjustable switching frequencies up to 768kHz, and hardware fault monitoring for overcurrent, thermal, and power supply conditions. The board can be powered from a 7V–26V external power input (up to 28V max) and includes an onboard step-down regulator to supply 5V to the Raspberry Pi. Applications include DIY audio systems, smart home installations, multi-room streaming setups, and embedded audio products.
Louder Raspberry Hat Plus specifications:
- Compatibility – Raspberry Pi 2, 3, 4, 5, Zero, and potentially all other Raspberry Pi models with 40-pin header
- Audio Hardware
- DAC/Amp – 1x (Stereo) or 2x (2.1-channel configuration) via Texas Instruments TAS5825M I2S DAC with integrated Class-D amplifier
- Output Power
- 2x 32W (8Ω, 1% THD+N) @ 20V
- 2x 45W (4Ω, 1% THD+N) @ 20V
- 1x 53W (4Ω, 1% THD+N) @ 20V in PBTL (Mono) mode
- 2x 32W (8Ω) + 1x 53W (4Ω) subwoofer driver only on 2.1 Channel 2X model
- DSP
- Digital volume/gain control
- 15-band parametric EQ per channel
- 128-tap FIR filter
- 3-band Dynamic Range Compression (DRC)
- Automatic Gain Limiter (AGL)
- Smart Excursion, Smart Thermal, Smart Bass, and SmartEQ
- Connectivity via 40-pin GPIO header
- I2S for audio interface (Clocks: GPIO 18, 19; Data: GPIO 19)
- I2C for digital volume control, gain control, and DSP configuration (Addresses 0x4c – 0x4f)
- Integrated IR receiver connected to GPIO 17
- Misc – Infrared (IR) input via GPIO 17 (1X model only)
- Power
- 7V to 26V DC via external power supply
- Onboard buck regulator for 5V at up to 3A (for Raspberry Pi)
- Overcurrent, DC fault, PVDD under/overvoltage, and 4-level thermal warnings
- Dimensions – 65 x 56 x 20 mm
Since the TI TAS5825M DAC+ AMP isn’t supported by the standard Raspberry Pi OS, you’ll need to install a custom driver from the project’s repository, which also includes PCB schematics and detailed software setup instructions for enabling and configuring the board.
This setup is said to typically take about five minutes and a single reboot to enable full ALSA control over volume levels and the hardware DSP features. For the infrared receiver, you simply add a specific GPIO overlay line to your config.txt file. Once the driver is active, the board is fully compatible with popular audio platforms like Volumio, Moode Audio, and Logitech Media Server (LMS). More information is available on the documentation page on Hackaday.
Previously, we have also written about Sonocotta’s HiFi-Amped, which features dual PCM5100 DACs and dual TPA3110D2 class-D amplifiers for stereo output. Sonocotta also designed the ESParagus Media Center, another compact media center built around an ESP32 and a class-D amplifier.
The Louder Raspberry Hat Plus is currently available on Tindie, starting at $25 for the 1X configuration and $30 for the 2X configuration. Sonocotta also offers optional add-ons, including OLED and TFT display HATs for showing album art, volume levels, and track information. A 65W power adapter can also be purchased from the same store. Sonocotta mentions that the board is also available on Elecrow, but as far as I can see, it’s not currently listed, possibly due to Lunar New Year holidays in China.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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