["brand new and high quality\nFeatures:\nFE-6J1-2.0B designed for music enthusiasts design and development. Today, due to the improvement of people's living standards, the pursuit of quality has been improved, in the 1960s, can hear the sound of music has been very satisfied, and now, what we need is high-quality music, including automotive CD, lossless format WAV, APE, FALC. But sad reminder that: often not download these lossless formats of music, but to hear high-fidelity sound quality, which you may for wish to consider this our forward-grade fever, although it is not 100 percent lossless sound reduction, but in absolutely enhance the sound quality is very good. It will bring you an unexpected surprise!\n1.AC 12V input:\nUsing DC5.5 * 2.1 socket, 12V AC power adapter is available, you can also use 12V AC transformer, if you use 12V AC transformer, power lines need to solder on the circuit board. Remember: You can not use a for DC power input, otherwise it does not work!\n2. the left-channel input / right channel input:\no signal input, can be connected to mobile phones, computers, M3, MP4, and other music players.\n3. the output of the left channel / right channel output:\nThe o signal output terminal can be connected to the o signal input amplifier, power amplifier boards, to provide post-amp Bile flavor of music to enjoy!\n4.the power switch / volume knob:\nThe knob counter-clockwise to decrease the volume beginning, when the volume down to the minimum, if it continues to rotate until the \"ticking\" sound, then the power off, the light goes off.\nIn the off state, turn the knob clockwise to hear \"tick\" sound, light is on, the power is turned on, then the volume is minimal, then continue clockwise rotation is to increase the volume.\n\nSpecification:\nSize: app.7.7x7.5x5.7cm/3.03x2.95x2.24in\nColor: As pictures shown\nQuantity: 1 Set\n\nNote:\nPlease allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid.\nDue to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!\n\nPackage includes:\n1 Set x for Valve Tube Preamp Kit\nor\n1 Set x for Valve Tube Preamp Housing"]