Good Features: 4 channel line mixer has low noise, high sound quality, strong configuration, and it is small but powerful. With A Wide Range of Applications: Our 4 channel headphone amplifier is suitable for mixing most electronic instruments and microphones. Independent Volume Control: The independent volume control allows each audience to determine their own volume through a dedicated output volume control knob. Suitable for DC 5V Power Supply Mode: 4 channel audio mixer is applicable to DC 5V power supply mode and convenient for customers to use in various occasions. Simple Operation Mode: Each channel has added a switch button, which makes the switch between mono and stereo audio input more convenient and intuitive.