| 摘要 |
The digital audio amplification system described herein uses a pulse density modulation (PDM) encoded 1-bit digital audio signal as the input signal, which is, for example, encoded based on the DSD (Direct Stream Digital) standard or another analogue method, and reproduces it for an acoustic system in an analogue shape, using low-pass filtering, voltage and/or current amplification of digital signals, and, if necessary, conversion of the frequency and/or specification of the time offset of the input signal. The audio amplification system includes a DSD/PDM signal receiving system and a circuit for correcting the time offset of that signal, which can also work as a frequency converter. The achieved PDM signal is directed to a switching circuit, which copies the shape of the input signal with a bigger output current and a voltage amplitude selected by the user. The signal exiting the switch is suitable as an input signal for acoustic systems (speaker, headphones) after low-pass filtering, and the mechanical or electrical parts of the acoustic system itself can serve as low-pass filters. The audio amplification system may be an autonomous component or form an integrated whole with an acoustic system (speaker). |
