【Stereo sound source】Amplifier 4 channels, with independent volume knob, can be used for up to four outputs: no sound burst, minimum distortion at maximum volume. When all four headphones are connected, the signal is not lost. The 4-channel headphone amplifier will be excellent, allowing up to four people to monitor the mix simultaneously for tracking. 【Stereo quality】Mini stereo amplifier with 4X 1/4 "stereo headphones TRS output connector jack, 1/4" TRS source input connector jack. ◆ Stereo ◆: You must use 1/4 ”TRS stereo audio cable for male-to-male connector for input and output connection. 【Lightweight and simple】Sturdy metal structure headphone mixer, tight connection, smooth operation knob. Ideal for stage and indoor performances or applications that require multiple headset connections. 4-channel stereo headphone amplifier for use with all types of headphones. DC 12-Volt adapter included. 【Worry-Free Service】: Our products are rigorously tested to ensure that each has extraordinary stability. If you have any questions about our products, you can contact us at any time, and our customer service will reply within 24 hours.