Stereo sound: The sound quality of the preamplifier is very good, it can be used for a long time. you can enjoy music without having to worry about noise. Small size: This preamplifier is small in size and light in weight, which can be easily placed in a pocket or backpack without taking up too much space. This circuit can be used when the sound of your device is small when connected to the power amplifier. It is suitable for small audio signal amplification, the amplification factor is 10 times (20db), and the front 3.5mm interface can be connected to headphones; Power supply: DC9-19V (Power supply not included) The amplifier chip is a dual op amp NE5532 Colour: Black material: metal Input and output are 3.5mm ordinary headphone jack and lotus jack TAKE A LOOK!:NE5532 Preamplifier music audio signal Pre amp amplifier 20db gain 3.5MM Headphone phone sound Volume Control dc 12v Preamp: the preamplifier has a preamplifier, which can be used as a preamplifier for your headphones or audio