What is it

Amped-ESP32 combines ubiquitous ESP32 with a PCM5100 HiFi DAC teamed up with a highly efficient TPA3110D2 D-class amplifier. It brings all the best from the HiFi-ESP32 model and adds an onboard amp to form a complete solution that can be paired with speakers directly. It uses an external power source to feed hungry amps and the host MCU using an onboard drop-down converter. It has similar power capabilities to the Louder-ESP32 model, but it is much simpler to use since it only needs a valid I2S signal to operate, so a simple book example code will do it.

Motivation

I spent the last few years developing different solutions based on ESP devices. It all started with ESP8266, where CPU power is not really sufficient to do real-time decoding, so you're limited to a rather simple ding-dong business. Then ESP32 came, bringing two much more capable cores, so you have a powerhouse to handle communication and decoding at the same time. Perhaps most importantly it also came with SPIRAM, so you can do decent buffering (essential for streamed content). Now new ESP32 C-Series and S-Series chips are entering the market, and their potential is mostly unrealized as of today.

I created ESP32 Audio docks and subsequently development boards, to be able to quickly prototype for the whole range of ESP8266 and ESP32 chips, starting with the simplest finger-sized toys and going all the way up to full-sized speakers.

Recently I went a rabbit hole of Home Assistant integrations and discovered different ways ESP32 with a decent DAC can be integrated into complex Home setups.

Onboard PSRAM

Audio streaming requires proper buffering to work, even with 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.

Features

	HiFi-ESP32	Loud-ESP32	Amped-ESP32	Louder-ESP32
Image (ESP32)
MCU	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard	ESP32-WROVER-N8R8 onboard
Image (ESP32-S3)			coming soon
MCU (S3)	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	Stereo I2S DAC (TAS5805M) with built in D-Class amp
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)
Output (8Ω)	Non-amplified stereo output	2x 3W	2x 25W (8Ω, 1% THD+N) at 22V	2x 25W (8Ω, 1% THD+N) at 22V
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
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
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)

Board Pinout

Amped-ESP32

Ethernet

Optional peripheral

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 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 Plarformio 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 IDE automatically.

Arduino IDE

Follow the ESP8266Audio library guide. Default settings will work out of the box with ESP8266 and ESP32 boards. For ESP32C3 and ESP32S2 board please adjust the pinout according to the above section

ESPHome and Home Assistant

Being an ESP32-based device, you can easily integrate it into your Home Assistant using ESPHome. Start with esphome web installer, which will give you ESPHome base install and WiFi configuration in minutes. Some S2/S3 boards have issues with we-installer, you may need to use Adafruit flasher instead with binaries pulled from the HA.

Next, navigate to your Home Assistant (assuming you have your ESPHome integration installed), and adopt the newly created node

ESPHome will give you ESPHome configs for Solo board running with ESP32-S2/S3, as well as Duo/HiFi-ESP and Amped ESP working with ESP32.

Few words of explanation.

• media_player publishes the media player into the Home assistant, so you can use it together with the native player or Music Assistant. You have a volume knob in the HA as well.
• 
• Volume set up to 50% on player start. Especially for Amped-ESP32, this is helpful :)

Bonus - automation example

The true power of the native speaker in the eHA is the use of automation. One example that I find useful. This simple automation will be pronounced every hour between 8 AM and 9 PM. Another one is used to pronounce bedtime, you get the point...

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.

All ESP32-based boards are tested with Squeezelite-ESP32 software, which can be flashed using nothing but a web browser. You can use Squeezelite-ESP32 installer for that purpose.

How to flash and configure ("ESP Audio Duo", "HiFi-ESP" and "Amped ESP")

Use Installer for ESP Audio Dock to flash firmware first. It has been preconfigured to work with ESP Audio boards and will configure all hardware automatically.

Select the correct device first
Connect the device to the USB port and select it from the list
Press Flash and wait around 2 minutes
(Optional) You may enter the serial console to get more information
Device is in recovery mode. Connect to squeezelite-299fac wifi network with squeezelite password (your network name suffix will be different)
When redirected to the captive portal let the device scan wifi network and provide valid credentials
You can use provided IP address (http://192.168.1.99/ on the screenshot) to access settings page
(Optional) You may change device names to something close to your heart
Exit recovery

You can use it now

Bluetooth	Spotify Connect	AirPlay	LMS Renderer

Hardware

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

Amped-ESP32 and Amped-ESP32S3

Amped-ESP32

ESP32	ESP32-S3
	coming soon

Optional SPI Ethernet module

Every board has a header that allows to solder in W5500 SPI Ethernet module that is very easy to find. The only downside is that with the module installed board will not fit the case, unless it is cut to accomodate extra height.

HiFi-ESP32(S3)	Loud-ESP32(S3)

Amped ESP power considerations

On the latest boards (starting from Amped-ESP32), I switched to barrel jack with thick middle pin with a 2.5mm pin, it’s a bit unusual but still common enough in the laptop world. It is far more comfortable in handling high currents, and importantly, much more sturdy and resistant to desoldering.

The power adapter specs depend on the speaker you're planning to use. DAC efficiency is close to 100%, so just take the power rating of your speaker (say 2x10w), and impedance (say 8 ohms), and you'd need at least 9 volts rated at 1.2 amps per channel, round up to 3 total amps.

It is not recommended to go beyond the voltage your speakers can handle, otherwise, the amp will blow your speakers in no time.

Case

The Amped-ESP32(S3) is mechanically compatible with Raspberry Pi 4 cases, tested with transparent ones. Also, community members created a few 3-D printable designs that can be found here and here

Amped-ESP32