What is it?

Raspberry HiFi Plus Hat is an upgraded version of the base model that uses a more advanced PCM5122 DAC and adds an audio-grade PCM1863 ADC onboard. The main benefit of using PCM5122 is a built-in digital volume control that makes sure that audio resolution is not lost at low volume. It also has built-in DSP with 6x BQ filters, but software support in Linux for it is absent at the moment, so you might need to develop it yourself (or wait for it to be added by the community).

The HiFi Plus Hat is fairly similar functionally to HifiBerry DAC+ ADC, but developed from scratch to validate DAC/ADC schematics for the sister product based on the ESP32

Key features

• PCM5122 DAC with line-out level output
• -112 dB typical noise level
• 2.1V RMS output
• Up to 32-bit resolution
• Up to 384 kHz sampling rate
• Digital volume and analog gain control
• Built-in DSP with 6xBQ filters, DRC, AGL

• I2S + I2C interface

• PCM1863 ADC with line-level and analog mic inputs

• -110 dB typical noise level

• 2.1V RMS output

• Up to 32-bit resolution

• Up to 192 kHz sampling rate

• Software-controlled gain (-12..32 dB)

• I2S + I2C interface

Why did I build it

I'm a huge fan of smart home solutions, specifically based on the Home Assistant ecosystem. With the Sendspin protocol introduction, it becomes possible to ingest external audio sources (Vinyl player, CD, etc) into the Music Assistant, so that they later can be distributed across connected speakers. HiFi Plus Hat is my first approach to this problem, based on the Raspberry platform (for ease of prototyping), and a stepping stone before an ESP32-based device with similar functionality can be created

Use cases

Raspberry HiFi-Plus Hat is a flexible, open-source audio platform designed to fit into both smart homes and custom audio projects.

• Smart Home Audio, TTS & Automation Node Integrates with Home Assistant and Music Assistant for high-quality playback, text-to-speech, and event-driven announcements. Functions as both an audio endpoint and a networked automation node for sensors, triggers, and smart home workflows. With added ADC, it also allows you to ingest audio sources (vinyl or CD players) into smart home audio solutions, serving as a bridge between old audio gear and modern smart homes
• Multi-Room Audio Infrastructure Use HiFi Raspberry Plus Hat as a Snapclient server and endpoint for perfectly synchronized distributed audio. Ideal for open, vendor-neutral whole-home or commercial audio systems.
• Standalone Network Player & Streaming Hub Run LMS/Squeezelite for a self-contained streaming device supporting Spotify Connect, AirPlay, and Logitech Media Server — no external computer required.
• Embedded Audio Processing & DSP Platform Execute real-time digital signal processing, filtering, effects, or audio analysis directly on-device. Suitable for smart speakers, alert systems, acoustic sensing, and custom audio interfaces.
• Educational Platform for Systems & Networking A practical teaching platform for embedded Linux-style workflows without full SBC overhead — covering networking, streaming protocols, real-time processing, IoT architectures, and open-source audio systems.
• Rapid Prototyping for Connected Products Designed for fast iteration of networked hardware products — from smart audio devices and notification systems to interactive kiosks and connected consumer electronics.
• Open Platform for Custom Products & DIY Builds With fully open firmware and tooling, HiFi Raspberry Hat provides a flexible foundation for personal projects, research platforms, or commercial device development.

Features

	HiFi Raspberry Hat	Raspberry HiFi Plus Hat
Image
Compatible with	Every Pi	Every Pi
DAC	PCM5100A 32-bit Stereo DAC	PCM5122 32-bit Stereo DAC
Output	2.1 VRMS Line level output -100 dB typical noise level	2.1 VRMS Line level output -112 dB typical noise level
IR input	✅	✅
ADC	❌	PCM1863 ADC with line-level and analog mic inputs -110 dB typical noise level
DSP features	❌	Digital volume, analog gain, 6x BQ filters, DRC
Mechanical dimensions (WxHxD)	65mm x 30mm x 15mm	65mm x 30mm x 15mm
Power requirement	5V from the host Pi	5V from the host Pi

⚠️ HiFi boards require an external amplifier or active speakers; you can't connect passive speakers to it.

💡 Need to connect speakers as well? Check out Amped Raspberry Hat and Amped Raspberry Media Center

💡 Need only speakers output? Check out Loud Raspberry Hat and Loud Raspberry Media Center

💡 Need more powerful DSP? Check out Louder Raspberry Hat, Louder Raspberry Hat Plus and Louder Raspberry Media Center

Board Pinout

How to use

You need nothing more than an SD card with a Raspbian image and a USB-C power brick. You can use any distribution you like. The only change you need to make to enable hardware is to add 3 lines to the /boot/config.txt

dtoverlay=gpio-ir,gpio_pin=17 dtoverlay=hifiberry-dacplusadc

To test the line input capture you may use the below snippet arecord -D hw:0,0 -f S16_LE -r 48000 -c2 | aplay -D hw:0,0 -f S16_LE -r 48000 -c2 --buffer-time=50000

Other software options

The project repository provides a few examples with build instructions, including Volumio setup instructions, among others.

Hardware

Please visit the hardware section of the project repo for board schematics and PCB designs. Note that PCBs are shared as multi-layer PDFs as well as Gerber archives.

IR reader

Please follow this guide to configure an IR reader

USA shipping Update

Due to the new tariffs introduced by the Trump administration, standard shipments are temporarily on hold. However, shipping to the US has now resumed via UPS, though rates are currently quite high.

Sponsorship & Community Support

If you’re working on an open-source project, an educational initiative, or any pro-bono/volunteer effort, feel free to reach out for sponsorship details. I’ll do my best to provide discounts or even free boards.

Custom Design & Consultation

If you’re interested in a custom design based on, or inspired by, my boards, I also offer contract design work and consultation when needed.

Most orders are shipped the next business day morning. All shipments are tracked. Delivery time in the EU is 3-7 days, outside 2-3 weeks, depending on the distance. After 30 days, the package is considered lost - reach out for a refund or replacement.