Input Audio: Coaxial or Toslink digital audio. Input audio connector: Toslink, 1XRCA(Coaxial). Product B: 1 DAC Converter+1 Optical Cable+1 USB Power Cable. Product A:1 DAC Converter Only. The digital-to-analog Converter and Bluetooth converters convert optical or Coaxial Digital Audio Signals and Bluetooth receivers into Stereo analog signals.
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