Do you have a question about the Aiyima A08 PRO and is the answer not in the manual?
Visual indicator of audio signal strength on the amplifier.
Control for adjusting the low-frequency response of the audio.
Control for adjusting the high-frequency response of the audio.
Primary control for powering the device and adjusting the overall volume.
Port for connecting the external antenna to improve Bluetooth signal reception.
Input connectors for analog audio signals, automatically switches with Bluetooth.
Standard headphone jack for audio output, not suitable for earphones.
Terminals for connecting passive speakers to the amplifier's output.
Connector for the DC power supply input, maximum 48V.