INTERIOR STRUCTURES OS THE POCKET HIFI Aim to broadcast the audio of HIFI level fro a portable player the size of a cigarette pack, the assembly such as circuit board, chip, even the capacitor must be selected carefully. The traditional player used the signal chip whose main structure was made of MPU, DAC and earphone amplifier. This structure always processed the audio at the cost of great loss. This kind of voice sounded stiff, rigid and apathetic. It could make your ears feel tired, if you heard it for a long time. The internal structure of the Pocket HIFI player was much more complex than traditional MP3 player. In the Pocket HIFI player, the original audio must pass through 8 units from input to output for the sake of getting the perfect voice.