Usage Tips:Basic Parameters: 7 band sound equalizer preamplification gain, 4580 op amp provides 5 times amplification (14dB); input impedance 20K, output impedance 600 ohms.Compatible with Headphones: This sound equalizer ear amplifier part of the NE5532 composed of type 47 headphone driver circuit, easy to drive all types of headphones, adjustable high and low.Aluminum Alloy: The 7 band car sound equalizer is made of aluminum alloy, high strength, stable performance, DC5V12V power supply, dual channel sound.3.5mm Interface: 3.5mm input interface supports 4 pole plug, the output connects to the headset with a microphone, which can be used on cell phones for normal voice calls, and another terminal with a group interface is available.Control Range: 7 band equalization circuit control range 12dB, equalization band: 60HZ,150HZ,400HZ,1KHZ,3KHZ,6.5KHZ,15KHZ, by TI or ST TL074 composition.