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Beaglebone Audio Amplifier

posted Jun 28, 2013, 12:32 PM by Daniel Nilsson
Below is a picture of the first prototype of the Beaglebone Audio Amplifier Cape! The design is working and playing audio from the network over RTP with the help of Pulseaudio. Audio output appears to work well, power depends on input voltage, I've measured around 2x25W at 24V input voltage.

A bit more on the design, the design is a combination of 3 different blocks;
  1. Power supply for the Beaglebone
    The cape is supplied with a DC voltage between 12V and 28V, the audio amplifier is using this voltage is it's supply voltage. In order to not need a separate 5V supply for the Beaglebone itself this, the cape supplies 5V (up to 2.5A) to the Beaglebone base board.
  2. Audio codec, TI TLV320AIC3106, which supports both audio capture (line level) and audio output. This codec is fully supported under Linux
  3. Audio Amplifier, TI PA3118D2, which is a Class-D audio amplifier. This amplifier takes the line level audio from the codec and makes it possible to connect speakers directly to this cape.

The initial application I will be using this for is multi-room audio players. Using for example Pulseaudio and the RTP protocol it is possible to stream audio over the network and playback audio using this "cape" in several locations at the same time. The Pulseaudio protocol takes care of keeping audio synchronized between the all players, which is a requirement when playing in multiple locations at the same time.

The design could potentially be produced in lower quantity depending on interest, I haven't investigated that yet...

Daniel Nilsson,
Jun 28, 2013, 12:32 PM