Product DetailsLINEPAUDIO B877 personal listener. Designed for players who want to listen to their voices via headphones or earphones, such as their vocal and musical instruments, mainly for drummers, who need to mix click tracks with listener signals. Church choir singing and others needs to listen to the sound of their music. All 3 stereo channels personal monitor desk headphone mixer,Three input channels are outputted by 1/4 and 1 / 8(6.5 and 3.5 mm) of headphone holes through various level controllers, and the microphone channel and device output are connected to ground switches. Easy to eliminate the current ground buzzing noise. This product is an ideal choice for live band and church musicians as well as studio musicians and singers. It has the ability to customize the main music and the voice and instrument input of musicians. Make the product become an effective and multifunctional listening device.Line input: 1/4 "TRS stereo Jack for connecting line level signal sources, such as mixer listening / auxiliary output, cassette player output, CD player output, and etc. Ground connecting: plug jumper to disconnect the chassis grounding input of microphone pin 1 and the microphone passes through.The microphone: XLR Jack is in parallel with the microphone input Jack (hardwired) for delivery to the mixer or other microphone-level input device.Microphone input: XLR balanced Jack for connecting capacitors or moving-coil microphones.Device input: 1 / 4 "TRS stereo Jack for connecting device or line level signals, such as guitar processors, keyboards, musical instruments, keyboards, or previous outputs of musical instruments.Mono / stereo jumper: select whether the input Jack is mono or stereo.Left / right output: transformer balanced XLR output from device input.Grounding route: a plug jumper used to disconnect the chassis from the output Jack of the 1/4 "TRS device."Mono / stereo jumper (located below the line input): select whether the line input Jack is mono or stereo.Note: the interface of the XLR Jack under MONO mode can be used for "Phantom Power" which is required to connect the mixer.Headset output: 1 / 4 "stereo Jack" and 1/8 "stereo Jack" for connecting stereo headphones or headphones.Line level: adjust the level signal from the line input to the headphone mixing.Microphone level: adjust the level signal from microphone input to headphone mixing.Inst. level: adjust the level signal from inst. input to headphone mixing.The line input is connected to a 1/4 "stereo or mono plug." If the plug is 6.35mm stereo, select the mono / stereo jumper set by stereo. The plug is a single-ended mono channel. Select mono / stereo jumper settings.Microphone input is connected to a dynamic microphone or capacitive microphone via a standard XLR cable. If you are using a capacitive microphone, you need to charge it with power from the mixer connected to the microphone Jack. This Jack transmits the phantom power from the mixer to the microphone. Connect the microphone through the Jack to the mixer as needed.Instrument input is connected to the guitar preamplifier output, keyboard or any stereo or monophonic instrument signal. Select stereo or mono.Product featuresspecificationsmax input level: -20 dB XLR,+40dB line,+15dB instrumentinst.input impedance:50K ohmsinst.output freq.response:10-30kHz+/-3 dBoutput impedance, hdphn:10 ohmsoutput impedance, inst:2 ea;100 ohms balancedgain:20 dB 1/4",50dB XLRhdphn freq. response:20-20 kHzs/n ratio:90dBpower:9-16VDC1/4 TRS stereo / mono listening input.The XLR microphone enters w/ pass-through.1/4 TRS stereo instrument input,.6.35mm / 3.5mm stereo / mono output.Net product weight: 447g.Weight after packing: 625 g.Product size: 130mm length X 85mm width X 38mm height.Packing size: 200 mm length x 180mm width x 55mm height.Packing list1X3 channel personal listener earphone listening mixer.1X110V -240V DC12V power supply (wire length is 100cm).