HiFiBerry 

Datasheet DAC+ ADC Stage

Overview

The HiFiBerry DAC+ ADC Stage is a high-resolution digital-to-analog and analog-to-digital converter for the Raspberry Pi (newer models with 40 pin GPIO connector). This is a special sound card for the Raspberry Pi, optimised for one specific use case: the best audio playback and recording quality. It is specifically designed for OEM applications that require flexible configuration options.
The board can be customise for your specific needs using additional I/O boards

Please note that this board isn’t available to end users. If you’re a business customer, please contact us to discuss your specific needs.

Facts

• Stereo input and output
• Fully balanced inputs and outputs via extension header
• Dedicated 192kHz/24bit high-quality Burr-Brown DAC
• Dedicated 192kHz/24bit high-quality Burr-Brown ADC
• Hardware volume control for DAC and ADC. You can control the input and output parameters using “alsamixer” or any application that supports ALSA mixer controls.
• Connects directly to the Raspberry Pi, no additional cables needed
• No soldering, comes as a pre-fabricated kit.
• Compatible with all Raspberry Pi models with a 40-pin GPIO connector
• Directly powered from the Raspberry Pi, no additional power supply. Power supply via I/O board possible if Pi’s power jack isn’t expose to the outside of your enclosure
• Three ultra-low-noise linear voltage regulators for optimal audio performance
• Low-jitter dual-domain clock for optimised clock decoupling from the Raspberry Pi
• Mic bias voltage for the use with electret microphones, 48V microphone power supply available via I/O board
• No anti-aliasing filter in the input path for best recording bandwidth
• Gold plated RCA output connectors (onboard-connectors can be removed on your request)

Hardware

Specifications

Configuration

To support the DAC+ ADC Stage, a Raspberry Pi Linux kernel of at least version 4.19.60 is required. Have a look at the documentation how to update the Linux kernel.

Overlay for config.txt:
dtoverlay=hifiberry-dacplusadcpro

Please make sure to use the most current Linux Kernel.

The following small script may help to set useful standard settings for the board.

#!/bin/sh

amixer -c 0 sset ‘ADC Right Input’ ‘{VIN2P, VIN2M}[DIFF]’

amixer -c 0 sset ‘ADC Left Input’ ‘{VIN1P, VIN1M}[DIFF]’

amixer -c 0 sset ‘ADC Mic Bias’ ‘Mic Bias off’

amixer -c 0 sset ‘ADC’ 24

amixer -c 0 sset ‘Digital’ 207

The script above sets both inputs to differential, no microphone bias (phantom power, 48V) and 0dB input gain. The last line sets the output (DAC) volume to 0dB. Please note that in this example the DAC+ADC Stage is the ‘card 0’ selected by the option ‘-c 0’ and has to be changed in case your card is not the first. This is typically the case, if the standard audio settings in RaspbianOS are used. Please check the output of ‘aplay -l’.

Hardware Setup

Connect the HAT and the IO board using the flat ribbon cable as shown in the following pictures. The cable is designed that the IO board to be mounted atop of the HAT and the Raspberry Pi in a case.

Pinout 2×10 Header

Media

Additional documentation

• 3D model (step)

Note that this board is not available to the general public. If you’re an OEM that requires a large number of these boards, please contact us.

Last updated: August 5, 2022