Low-Latency Multichannel Audio System (2 x 24 Bit stereo inputs, 4 x 24 Bit stereo outputs)

Description:

Multichannel audio system based on BeagleBone Green/Black and AD1938 audio codec by Analog Devices Inc. The audio system offers 2 x 24 Bit stereo ADCs and 4 x 24 Bit stereo DACs.

Features:

• 2 stereo ADCs and 4 stereo DACs
• Up to 96 kHz sampling rate with 8 audio channels (up to 192 kHz with 4 channels)
• 24 Bit word width
• Separate interfaces to ADCs and DACs
• Asynchronous sampling rates for playback and capture
• Up to 3,2 ms round-trip-time
• Mobile usage (the Beaglebone Green and the audio card both are supplied with 5V supply voltage)

Project Components:

• I²S sound card (CTAG face2|4)
• Forked BeagleBone Linux kernel 4.1 with sound card drivers and modified device trees
• Adapter card “bbg-cape” to connect the BeagleBone Black/Green with I²S sound card
• Adapter card “con-cape” with stereo jacks and headphone amplifier, not yet published due to some bugs
• BASH script for automatic evaluation of latency, THD+N, DNR, crosstalk and frequency response using GNU Octave
• Surround-Delay audio effect for demonstration
• Debian Wheezy SD card image for BeagleBone Green (evaluation script and demonstration effect is included)

Applications:

• Mobile sound studio (simultaneously record several inputs with different audio effects applied and preview them on different outputs in real time)
• Programmable effect device for various music instruments
• Open platform for DIY audio projects
• Eurorack analog I/O interfaces

The complete project is open sourced.
For more details visit our website or our hackaday project.
Feedback is welcome:)