Low-Latency Multichannel Audio System

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)Adapter card “bbg-cape” to connect the BeagleBone Black/Green with I2S sound card

• Forked BeagleBone Linux kernel 4.1 with sound card drivers and modified device trees

• 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:)

Homepage: http://www.creative-technologies.de/linux-based-low-latency-multichannel-audio-system-2/