Audio Mixer 4 Way The advantages that distinguish AM-J4 Audio Mixer are the built-in HiFi AMP and USB C Power Port. With the HiFi Analog AMP, Mixer could mix and amplify up to 4 channels of both stereo and mono audio sources at the same time, and drive maximum 600ohm impedance headphones and deliver ultra-clean sound without distortion and noise. The Mixer could be easily powered by a cellphone charger (Min. 5V 1A, Not Included) and USB C charging cord (Included). Support 4-Channel Line-In Audio Input Support Simultaneously Input of Stereo and Mono Signal Built-In HiFi Analog AMP for Optimal Audio Performance Ultra-USB C Powered Independent Volume Control Knob Premium Aluminum Alloy Body Please note that the Audio Mixer does not support microphone input. 【4-in-1-out Function Use】If you need a mini audio mixer with 4 channels of audio ( electronic musical instruments, computers, game consoles, etc.) to be integrated into channel output, this stereo-line mixer is perfect for you. 【Multi-Application】Each channel of the audio mixer has an independent volume control, It mixes multiple channels into track, suitable for your Keyboards, Small stage setups, drum sets, or sub-mixes. 【Ultra-Low-Noise】With full Aluminum alloy housing, interference is fully isolated to the highest sound quality at all output levels, has ultra-low noise operability, and provides excellent audio performance. It is ideal for desktop Audio systems or recording. 【Easy to Use】audio mixer is equipped a USB C port for the power supply, you could easily power the mixer with smartphone charger or laptop charger. The audio mixer collects sound from many different sources (guitar, bass, and keyboard) for monitoring.