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