1. Control range: Control range of 7-b equalization circuit is 12dB. Equalization frequency b: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz, 15KHz, composed of TI ST TL074. 2. Basic parameters: 7-b sound equalizer preamplifier gain, 4580 classic operational amplifier provides 5X amplification (14dB); The input impedance is 20K, the output impedance is 600 . 3. Adapting earphones: The NE5532 constitutes the balanced earphone amplifier of the 47 earphone driver circuit, which can drive various earphones with adjustable height. 4. 3.5mm interface: The 3.5mm input interface suppts a 4-pole plug, the output is connected to a headset with a microphone, which can be used f nmal voice calls on the mobile phone. In addition, there is a terminal of RCA interface. 5. Aluminum alloy material: 7-b audio equalizer is made of aluminum alloy, with high strength, crosion resistance, stable perfmance, DC5V - 12V power supply, dual channel sound. It is widely used or car audio or mobile phone or computer or game console other devices. col:Black Material:metal Package Contents: 1 x Headphone Amplifier Mixer Only the above package content, other products are not included. Note: Light reflection different displays may cause the col of the item in the picture a little different from the real thing. The measurement allowed err is 1-3cm.