Feature: 1. The circuit chip is fully upgraded, smart noise reduction, sound quality fidelity.Imported potentiometer knob, rigorous testing, which has long life and good hand feeling. 2. 4 input channels, each channel is independent, capable of treble and bass adjustment, gain adjustment and reverb adjustment. 3. The mixer is equipped with a USB socket, which can be directly inserted into the U disk to play music, which is easy to plug and play. 4. The mixer has a built in BT module, which can be connected with BT enabled mobile phones,computers,tablets and other devices. 5. Adaptation to a variety of devices, with professional input and output interfaces, rich in usage. Specification: Item Type: Audio Mixer Material: ABS, Metal Total Harmonic Distortion: 0.1% S/N: ≥-80dB Input/output Impedance: 1. MC.: 2.4KΩ; 2. Mono: 11KΩ; 3. Stereo: 100KΩ Parametric Equalizer: 1. High: 12KHZ; 2. Low: 80Hz Power Supply Voltage: DC5V BT Protocol: 4.21. Monophonic Input Channel 1/2 Composite Microphone Line Input Jacks: Used to Connect Microphones and Other Audio Equipment, Support Kalong Plug and 6.35mm Plug. 2.48v Phantoms Power Switch Indicator Light: Press This Switch, the 48V Phantoms Power Indicator Light is On, and the DC 48V Phantoms Power Supply is Supplied to the Karon Interface for Condenser Microphone Use 3. Mono Input Channel 2 Guitar Line Input Switch: Used to Switch Different Audio Sources Input to the 6.5mm Jacks of Channel 2. After Pressing This Switch, Channel 2 Can Be Directly Connected to a High Impedance Audio Source Device, Such As Electric Guitar and Bass Bass. when This Switch Pops Up, You Can Connect Low-impedance Audio Equipment. 4. Gain Knob: Adjust the Amplification Factor of the Amplifier to Match the Sensitivity of the Input Signal. 5. Treble and Bass Knob: High Quality 2 Stage Tones to Adjust the Timbre of the Sound. 6. Effect Send Button: Press This Button, the Sound of the Channel Will Be Sent to the Built-in Effector of This Machine. 7. Volume Knob and Peaks Indicator: Adjust the Channel Sent to the Main Output, Headphone Volume. if the Peaks Indicator Light Flashes, It Means That the Signal Begins to Be Distorted, You Should Adjust the Gain Knob to the Left to Reduce the Signal Gain; (Note: the Gain, Tones and Volume Knob Functions of the Stereo Input Channel Are the Same As the Mono Input, Please Refer to .) 8. Signal Switch Button for Mp3 Player and CH3-4 Channel: Press This Button, the Signal from Mp3 Player Enters CH3-4 Channel, and then Mixes to the Main Output Channel; at This Time, the Signal Connected to the CH3-4 Channel Plug is Cut off . Popping Up This Button, the Signal of the Mp3 Player Directly Enters the Main Output Channel, and the Signal Connected to the CH3-4 Jacks Enters This Channel and then is Mixed to the Main Output Channel. 9. Built in High Quality Digital Effect Processor to Render the Sound of the Channel Del: Adjust the Size of the Sound Effect Space and the Time Interval of Repetition; Rep: Adjust the Number of Echoes of the Effector; 10.Main Output Volume Knob: Adjust the Volume of the Main Output; 11. Headphone Volume Knob: Adjust the Volume of the Headphone Output; 12.3.5mm Headphone Output Jacks 13. Power Indicator. 14. Main Output Level Indicator Light: Flashing Green Means the Signal is Normal, Flashing Red Means the Signal is Distorted, Please Reduce the Volume. 15. BT,mp3 Player: the Latest 1 Generation of BT Mp3 Integrated Core Supports Mp3, Wav, Lossless Ape, Flac and Other Audio Formats to Play: BT 4.2 Standard System, Support Cover Teeth 2.1+EDR: When Using a USB Cable to Connect to the Computer, You Can Used As a Usb Sound Card to Play Music and Record 16.The Input Interface of the Stereo Input Channel: There is a Socket and a 6.5mm Socket, Divided into Left and Right Channels 17. Main Output Socket 6.35mm Socket: Supports Balanced and Unbalanced Connection Methods, Used to Connect to Active Speakers or Power Amplifiers. 18.Lotus Socket for Recording Output; 19.Mode Selection Switch: when Connected to the Computer's USB Interface for Power Supply, This Mode Switch Bounces, the MP3 Player Enters the USB Sound Card Working Mode, and when Pressed, It Enters the U Disk Playback BT Working Mode; when Using the Mobile Power Supply or Adapter to Supply Power, to Press This Mode Switch, the Mp3 Player Enters U Disk Playback,BT Working Mode. 20. Micro Use Socket: Connect to the USB Interface of the Computer for Power Supply and Use As a USB Sound Card. It Can Also Be Powered by a Power Adapter or Mobile Power Supply, Specification 5V,1A.. Package List: 1 x Sound Card1 x User Manual1 x USB Cable