Control Range: The 7-band equalizer adjustment range is ±12db, composed of TI or ST TL074 circuit, 60HZ, 150HZ, 400HZ, 1KHZ, 3KHZ, 6.5KHZ, 15KHZ seven frequency bands, the knob is in the middle as the origin, counterclockwise for attenuation, clockwise for boost. Basic Parameters: 7 band sound equalizer preamplification gain, 4580 classic op amp provides 5 times amplification (14dB); input impedance 20K, output impedance 600 ohms. Compatible with Headphones: 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. 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 lotus interface is available. Regarding the frequency description, 60HZ is heavy bass, 150HZ is bass, 400HZ is mid-bass, 1KHZ is mid-range, 3KHZ is mid-treble, 6.5KHZ is treble, 15KHZ is super treble, adjust according to personal listening preferences. Power supply: DC5V-12V, interface specification is 5.5x2.1, 5V power supply has a static current of about 390ma, 12V power supply has a static current of about 140ma, and power consumption is about 1.8w. Item Type: 7 Band Sound Equalizer Power Supply: DC5V-12V Interface Specification: 5.5x2.1 Input Impedance: 20K Output Impedance: 600 Ohms Equalization Circuit Control Range: ±12dB Equalization Frequency Band: 60HZ,150HZ,400HZ,1KHZ,3KHZ,6.5KHZ,15KHZ Colour:Black Material:Metal Package Contents: 1 x 7 Band Sound Equalizer 1 x USB DC Cable 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.