Audio player device and startup method thereof

A startup method, for starting an audio player device, the startup method comprising:

• setting all of a plurality of bits of audio data to a first logical value by software or a controller in the audio player device, wherein the audio data is converted into an audio signal by an output amplifier in the audio player device;
• gradually adjusting a level of a startup voltage by a startup circuit in the audio player device according to a reference voltage during a predetermined period, and outputting the startup voltage as a control voltage, wherein the control voltage is used to set a common mode level of the output amplifier;
• switching to output the reference voltage as the control voltage after the predetermined period has elapsed;
• and
• gradually switching a half of the bits to a second logical value.