1. EQ key: when playing USB / SD music, briefly press this key to switch between five EQ sound effects and select the EQ sound effect preferred by the user

 

2. USB / SD boot defaults to full disk circular playback. Press this key to switch to single song circular playback.

 

3. Stop key: when playing U / SD, press this key to stop playing. When you press it again, it will play from the first time of U / SD.

 

4. Rec recording key: when USB / SD is working, long press this key to record the sound of MIC port. The length of recording depends on the U disk or SD used

 

Depending on the capacity of the card; Short press this key when playing music USB flash disk with recording files to quickly switch to recording files for playback, which is convenient for users to quickly find recording files

 

5. BT / USB / SD mode: short press for the next song, long press for volume increase FM radio mode: short press for the next station, long press for volume increase In aux mode: press and hold the volume to increase

 

6. BT / USB / SD mode: short press for the previous song, long press for volume reduction FM radio mode: short press for the previous station, long press for volume reduction Aux mode: press and hold to decrease the volume

 

7. In USB / SD mode: short press to pause the play. In FM radio mode: short press to search the channel automatically

 

8. Mode key: short press to switch between Aux / USB / SD / BT / FM modes When playing a recording file, long press this key to delete the currently playing recording file

 

9. USB flash disk socket

 

10. SD card socket

 

11. LCD: it can display the song names of Chinese and English songs, copy the songs and the corresponding lyrics files into the USB flash disk at the same time, and synchronously display the lyrics of the played songs

 

12. FM radio antenna interface. In order to achieve the ideal reception effect, it is recommended to use 800mm long 22 wire diameter.

 

13. Battery power display interface: (when the detection voltage is lower than 5.8v, the battery symbol is not on, the first grid of 5.8v-9.5v flashes, one grid of 9.5v-10.5v is always on, and two grids of 10.5v-11.5v are always on,

 

11.5V or above indicates full power. Note that the current design maximum detection voltage should not exceed 22V)

 

14. Aux external signal input

 

15. Mic recording port

 

16. Left and right channel audio output

 

17-18. The power interface of the main board is pl ed in the positive and negative direction. Note: if there is a 78m05 element pasted with position 18, it means that it can work with 12V voltage. If there is 78m05 element pasted with position 18

19. The reserved data control expansion port is used for high and low level control with the power amplifier.

20. Reserved interface for optical fiber coaxial function.