Digital audio amplifier with PLL synthesized FM radio


Another open source hardware project by Dilshan Jayakody the digital audio amplifier with PLL synthesized FM radio:

This is high quality stereo digital audio amplifier with PLL synthesized FM radio receiver. Some of the high level specifications of this receiver are listed in below:

  • Audio output power: 4W + 4W (with 8ohm speakers)
  • Input sources: FM and 3 external stereo line inputs
  • FM frequency range: 88.00MHz – 108.9MHz
  • Supply voltage: 12V – 15V (2A current source is recommended)
  • Tone control options: Bass, Treble and Loudness control
  • Bass / Treble boost: 14dB
  • Bass / Treble cut: 14dB
  • Station memory: Preset 10 FM radio stations
  • FM tune options: Auto and Manual with 25 kHz steps

All the source codes and design files are available here.

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  1. I have doubts whether it should really be called a “digital audio amplifier”, would others like to weigh in? The uPC2002 seems to be an NEC work-alike of TDA2002, a bipolar tech class B linear audio amp. PT2314 seems to be from Princeton Tech (Taiwan) — this chip allows audio to be “controlled digitally”, but I’m sure there isn’t any DSP inside it. TEA5767 is a well-known FM radio chip. The audio pipeline seems to be analog from the FM output to the speakers. It is only controlled uh, “digitally”.

    So is the moniker “digital audio amplifier” accurate or inaccurate? Seems a bit of a stretch to me.

    A bit big if you ask me. I’d rather save some power with a class E audio amp.

  2. Agreed, this is not a Class-D amplifier, which would be my definition of a “digital audio amplifier”.

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