What is it

Amped Esparagus is a next step in the Esparagus media center line of devices. It is a device based on PCM5100 HiFi DAC (just like HiFi Esparagus) but adds a powerful and efficient D-class amp (TPA3110D2) so it can drive speakers directly. It has similar power capabilities to the Louder Esparagus, but it is much simpler to setup and use, since this DAC doesn't need any configuration steps to get going, just a valid I2S audio stream. Since it has an analog stage, you can use it either with a built-in amp or with an external amp, if prefer so.

It is highly efficient, but demanding for power when cranked, therefore it uses either a USB-C Power Delivery to pull up to 65W from the wall power adapter or external power source for NOPD variant.

It can be used both with Wi-Fi and Ethernet (to make sure bad Wi-Fi would not interrupt the stream)

Motivation

I did few audio projects in the past, some using ESP32, some using larger Orange Pi and Raspberry Pi devices. Each has its pros and cons, and with each iteration, I'm trying to focus on the details that were working best for me, while actually using them.

What I like about ESP32 is how lightweight it is. It barely draws power, so you may not care to turn it off at all. It boots in seconds and is ready for use in a snap. Still, it is capable and works at par with Linux SBC solutions for audio applications, while costing a fraction of their price. Combined with a proper Hi-Fi DAC you would not tell a difference to commercial devices standing side by side and costing much more.

Over the last few years, I have seen a few amazing software products created to deliver audio on the ESP32, like squeezelite-esp32 or  euphonium. Esparagus media center devices are designed specifically to run these great pieces of software and bring a new life into aging audio equipment that most of us have at home but do not use that much these days, since it is not working with Spotify and the family.

Onboard PSRAM

Audio streaming requires proper buffering to work, even with ESP32 500K of RAM it is a challenging task. All Esparagus boards are based on WROVER modules that have an onboard PSRAM chip.

Features

Features

	HiFi Esparagus	Loud Esparagus	Louder Esparagus	Amped Esparagus
Image
MCU	ESP32-WROVER-N8R8	ESP32-WROVER-N8R8	ESP32-WROVER-N16R8	ESP32-WROVER-N16R8
DAC	PCM5100A 32bit Stereo DAC -100 dB typical noise level	Dual I2S DAC (MAX98357) with built in D-Class amp	Stereo I2S DAC ( TAS5805M ) with built in D-Class amp	PCM5100A 32bit Stereo DAC working with TPA3110D2 D-Class amp
Power	5V over USB-C, 2x LP5907 3.3 V Ultra-Low-Noise LDO for analog section	5V from USB-C	Up to 20V from USB-C PD or up to 26V from generic power adapter	Up to 20V from USB-C PD or up to 26V from generic power adapter
Output, 4Ω	Non-amplified stereo output	2x 3W	2x 32W (4Ω, 1% THD+N)	2x 22W (4Ω, 1% THD+N) at 16V 1x 40W (4Ω, 1% THD+N) at 20V
Output, 8Ω	-	2x 5W	2x 22W (8Ω, 1% THD+N)	2x 25W (8Ω, 1% THD+N) at 22V
PSRAM	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)
Peripheral	WS2812B RGB Led SSD1306 128x64 OLED screen (optional)	WS2812B RGB Led SSD1306 128x64 OLED screen (optional)	WS2812B RGB Led SSD1306 128x64 OLED screen (optional)	8xWS2812B RGB Led SSD1306 128x64 OLED screen (optional) Rotary encoder with push button
Connectivity	WiFi BT4.2 BLE	WiFi BT4.2 BLE	WiFi BT4.2 BLE W5500 Ethernet	WiFi BT4.2 BLE W5500 Ethernet
Size	80 x 50 x 20mm	80 x 50 x 20mm	100 x 80 x 38mm	100 x 80 x 38mm
Software support	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config

Board Pinout

Audio

Peripheral - OLED Screen and W5500 Ethernet (Amped Esparagus)

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-radio 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 project to the board. Communication and proper upload method selection will be handled by IDE automatically.

Arduino IDE

Follow the ESP8266Audio library guide.

ESPHome and Home Assistant

Being an ESP32-based device, you can easily integrate it into your Home Assistant using ESPHome. Please find detailed instructions on the linked github

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

How to flash and configure

Use Esparagus Squeezelite-ESP32 installer to flash the firmware. It has been preconfigured to work with Esparagus boards and will configure all hardware automatically.

Please find detailed instructions on the linked github

Hardware

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

Boxed

Amped Esparagus NOPD

PCB

Amped Esparagus

Amped Esparagus power considerations

The Amped Espragus can be quite a power-hungry device, simply using 5V over the USB-C is clearly not an option. The intention for using a PD-enabled power adapter to run the board is simplicity and ease of use for customers. Ideally, you should supply a 20V 3.25 Amp capable power source, which is common for modern laptops (Dell, HP, and Lenovo have all tested and work perfectly). However, pretty much any 9V/12V/20V PD-enabled power adapter will work, most typically phone chargers with a quick charge option. The smallest of the family is a 25W model, which is plenty enough for a living space.

The interesting part was all the phone and laptop chargers I used for the test (around five different makes of each), sounded great, with no hissing, no popping. (Apart from the Apple ones, they didn’t work. Likely they have Apple-specific PD protocol). This is probably because modern devices have become so noise-sensitive that manufacturers have been forced to do good work on noise levels.

Tested and perfectly working models are (others may be available)

Model	Image
65W USB-C Lenovo ThinkPad Laptop Charger Replacement Power Adapter
65W 45W 20V 3.25A Type-C PD Laptop Charger
120W Gan Type-C PD Charger
45W Type-C PD Mobile Phone Wall Adapter

Because USB-PD is a bit of a Wild West in terms of standards, sometimes not everything goes as designed. Some people have run into this with power adapters that aren’t fully PD-standard compliant. In most cases, the worst that happens is the PD chip doesn’t trigger the 20V mode, so the Esparagus runs at around 5W per channel (which you might not even notice). One person reported that an older adapter somehow triggered just 1V on the USB-C power line, shutting down the Esparagus shortly after plugging in. Thankfully, we’ve confirmed that it works correctly with newer laptop adapters.

Amped Esparagus NOPD

The “hammer-style” solution I came up with is a new NOPD version of the Amped Esparagus that lets you use a barrel power jack to supply raw voltage directly. The catch? Standard 2mm pins can’t handle high currents, so I’ve gone with a 2.5mm pin instead — it’s a bit unusual but still common enough in the laptop world.

With this setup, you can supply more than the 20V limit of PD, giving you a bit more power for the speakers. You probably won’t hear much difference (thanks to the way human hearing works), but it could help larger speakers that need a bit more to really “open up." Other than that, the NOPD version works just like the PD version — no software changes are needed.

External voltage selection

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 take, otherwise, the amp will blow your speakers in no time.

The absolute maximum voltage for the TAS5805M DAC is 30V, but it is not guaranteed to be thermally stable in this condition.

OLED screen

All boards have an OLED screen header. Originally I had plans to have it as a feature (It is quite nice when using squeezelite since you can get quite a lot with existing plugins and settings). Later on, I disregarded this as a generally available feature, since it is quite a time-consuming task to solder it in place, and I had no really good idea how to fix the screen in place. Despite that, the header is present on every board revision and it works.

At this moment one can solder the compatible OLED screen and use it with the transparent front panel as a bedside clock or to display the current track (I prefer smoked glass for the final look of it). It takes a few minutes for a skilled engineer to solder it in place and a small strap of double-sided adhesive to fix it mechanically.

A	B	C

The final result is a nice and finished look

OLED models

Most of the 64x128 pixel OLED screen models that are very common among hobbyists will use compatible 30-pin ribbon connector with 0.7mm pin spacing, and they are really easy to desolder.

You can also find bare screens if you spend a minute. Below are the tested models, although there are plenty more out there.

Model	Image
0.96" OLED Display 128X64 SSD1306
1.3" OLED Display 128X64 SH1106

Software side

Although you're free to use it your way using the pinout above, I'd expect the most common case to be squeezelite, thus here are the steps you'd need to do

#	Description	Image
1	Update NVS settings in the Web UI (switch to recovery mode first) display_config = SPI,width=128,height=64,cs=15,reset=32,driver=SH1106,HFlip,VFlip spi_config = mosi=23,clk=18,host=2,miso=19,dc=4 You may need to replace SH1106 with SSD1306 depending on your model.
2	In the LMS settings install the SqueezeESP32 plugin
3	Update each speaker's settings in the LMS, and navigate to Display settings