What is it

The HiFi-ESP32 Plus represents the next evolution of HiFi-ESP32 boards, featuring the advanced PCM5122 DAC with built-in DSP capabilities. This board maintains the same audio quality as the original HiFi-ESP32 while adding powerful digital signal processing features, including parametric EQ (6 BQs per channel), DRC, and crossover functionality. The PCM5122’s flexible DSP engine can be configured for various audio enhancement scenarios, making it ideal for projects requiring sound tuning (why would you not), and opening the path to create 2.1 systems with PCM5122+PCM5102 master-slave config.

Key Features:

• PCM5122 DAC with integrated DSP
• Parametric EQ and crossover capabilities (for cascading DACs)
• Digital volume control (avoids loss of resolution compared to software volume)
• Advanced audio processing features (DRC)
• Same form factor and connectivity as HiFi-ESP32

Features

	HiFi-ESP32	Loud-ESP32	Amped-ESP32	Louder-ESP32	HiFi-ESP32 Plus
Image (ESP32)
MCU	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard
Image (ESP32-S3)			N/A
MCU (S3)	ESP32-S3-WROOM-N8R8 onboard	ESP32-S3-WROOM-N8R8 onboard	ESP32-S3-WROOM-N8R8 onboard	ESP32-S3-WROOM-N8R8 onboard	ESP32-S3-WROOM-N8R8 onboard
DAC	PCM5100A 32bit Stereo DAC -100 dB typical noise level	Dual I2S DAC (MAX98357) with built in D-Class amp	PCM5100A 32bit Stereo DAC working with TPA3110D2 D-Class amp TPA3128D2 amp starting from Rev H	Stereo I2S DAC (TAS5805M) with built in D-Class amp	PCM5122 32bit Stereo DAC with integrated DSP
Output (4Ω)	Non-amplified stereo output, 2.1V RMS	2x 5W	2x 22W (4Ω, 1% THD+N) at 16V 2x 32W (4Ω, 1% THD+N) at 20V 1x 40W (4Ω, 1% THD+N) at 20V (bridged)	2x 22W (4Ω, 1% THD+N) at 16V 2x 32W (4Ω, 1% THD+N) at 20V 1x 40W (4Ω, 1% THD+N) at 20V (bridged)	Non-amplified stereo output, 2.1V RMS
Output (8Ω)	Non-amplified stereo output	2x 3W	2x 25W (8Ω, 1% THD+N) at 22V	2x 25W (8Ω, 1% THD+N) at 22V	Non-amplified stereo output
PSRAM	ESP32: 8MB PSRAM (4MB usable) over 40MHz SPIESP32S3: 8MB PSRAM over 80MHz QSPI	ESP32: 8MB PSRAM (4MB usable) over 40MHz SPIESP32S3: 8MB PSRAM over 80MHz QSPI	ESP32: 8MB PSRAM (4MB usable) over 40MHz SPIESP32S3: 8MB PSRAM over 80MHz QSPI	ESP32: 8MB PSRAM (4MB usable) over 40MHz SPIESP32S3: 8MB PSRAM over 80MHz QSPI	ESP32: 8MB PSRAM (4MB usable) over 40MHz SPIESP32S3: 8MB PSRAM over 80MHz QSPI
Power	5V over USB-C, 2x LP5907 3.3 V Ultra-Low-Noise LDO for analog section	5V (up to 2.5A) from USB-C	Up to 26V from external PSU	Up to 26V from external PSU	5V over USB-C, 2x LP5907 3.3 V Ultra-Low-Noise LDO for analog section
Connectivity	WiFi + BT4.2 (except S3) + BLE Ethernet (optional module)	WiFi + BT4.2 (except S3) + BLE Ethernet (optional module)	WiFi + BT4.2 (except S3) + BLE Ethernet (optional module)	WiFi + BT4.2 (except S3) + BLE Ethernet (optional module)	WiFi + BT4.2 (except S3) + BLE Ethernet (optional module)
DSP Features	None	None	None	Advanced (EQ, DRC, AGL, etc.)	Parametric EQ, crossover, DRC

Onboard PSRAM

Audio streaming requires proper buffering to work, even with the ESP32 500K of RAM it is a challenging task. For that reason, most of the projects will require WROVER modules that have onboard PSRAM chips. All ESP32 Audio boards have an 8MB PSRAM chip onboard, connected via a high-speed interface. Any code using PSRAM with just work out-of-the box.

Board Pinout

HiFi-ESP32 Plus

Ethernet

Optional peripheral

Which software is right for me

Software samples

In the software section, two firmware examples are provided.

• esp32-i2s-bare is base I2S implementation based on ESP-IDF implementation directly.
• esp32-i2s-esp8266audio is based on the excellent ESP8266Audio library (it works with the whole ESP range, don't get fooled by the name), providing minimum code implementation.
• esp32-i2s-web-radio is based on the same library, providing minimum web-readio stream player. It expects a playlist as an input in the 'data' folder.

Platformio IDE

All samples are provided as Platformio IDE projects. After installing it, open the sample project. Select the proper environment based on your dock. Run the Build and Upload commands to install necessary tools and libraries, and build and upload the project to the board. Communication and proper upload method selection will be handled by the IDE automatically.

To spin up the PCM5122 DAC, you will need an I2C driver, which luckily was delivered by the community already in the basic shape. The fun part is going to be writing drivers to actually use all the DSP features.

I'm planning to start with basic EQ control and volume, then work up to the advanced stuff like crossovers. Planning to integrate it all into ESPHome so you can control everything from Home Assistant.

Also working on an Amped version that pairs the PCM5122 with a TPA3128 amplifier for folks who want the DSP features but with built-in power.

Squeezelite-ESP32

Squeezelite-ESP32 is a multimedia software suite that started as a renderer (or player) of LMS (Logitech Media Server). Now it is extended with - Spotify over-the-air player using SpotifyConnect (thanks to cspot) - AirPlay controller (iPhone, iTunes ...) and enjoy synchronization multiroom as well (although it's AirPlay 1 only) - Traditional Bluetooth device (iPhone, Android)

And LMS itself - Streams your local music and connects to all major online music providers (Spotify, Deezer, Tidal, Qobuz) using Logitech Media Server - a.k.a LMS with multi-room audio synchronization. - LMS can be extended by numerous plugins and can be controlled using a Web browser or dedicated applications (iPhone, Android). - It can also send audio to UPnP, Sonos, Chromecast, and AirPlay speakers/devices.

Squeezelite-ESP32 support is a work in progress, and as soon as the right DAC startup sequence is encoded into web-installer, I'll update this page.

Flashing ESP32-S3

ESP32-S3 boards have two ways of firmware update: (1) similarly to classic ESP32, they can be flashed over the built-in UART, or (2) uniquely for S3, over the built-in USB host controller. Since it is firmware-controlled, it may be disabled if not used (or, more commonly, not available with factory default empty firmware). When an unflashed ESP32-S3 device comes into a boot loop, with a USB-CDC device appearing and disappearing every second, and requires a special flashing initialisation sequence to get flashed:

• Press the IO0 (FLASH) button and keep it pressed
• Press the RESET button and release the FLASH button after
• ESP32-S3 will enter download mode, and the USB-CDC device will appear and stay available
• Run flashing routine as usual, either through web-serial or esp_tool
• This time, it is not possible to reboot the device over USB, so press RESET once more
• Device will boot normally into firmware, and if USB-CDC is enabled in the firmware, you will be able to flash it normally, download mode and reset sequence will work over USB.
• If you manage to flash firmware without USB-CDC support, you need to go through the above sequence once more

Hardware

Please visit the hardware section for board schematics and PCB designs. Note that PCBs are shared as multi-layer PDFs.

Case

HiFi-ESP32 Plus(S3) is mechanically compatible with Raspberry Pi 4 cases, tested by me with transparent ones.

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