Digital Audio Transfer

Bluetooth A2DP and USB Audio Class (UAC) are the most representative digital audio transmission schemes.

Terminology

• Source Device: The device that sends the audio (Transmitter), such as a smartphone or PC.

• Sink Device: The device that receives the audio (Receiver), such as a Bluetooth DAC or USB DAC.

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Supported Audio Format

When the receiver device connects to the source device, it sends the source device information about the supported audio formats, sample rates, bit resolutions, and codecs.

Audio Format Selection

The source device selects one of the audio formats the receiver device supports for audio transmission.

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Example #1 Bluetooth DAC

Information about supported audio formats is transmitted:

• 5K (Receiver) --> Android Smartphone

  • Supported codecs: SBC, AAC, aptX, aptX-Adaptive, LDAC

  • Supported sample rates: 44.1, 48, 88.2, 96 kHz

The smartphone selects one of the codecs and sample rates for transmission.