1. Control range: 7-band equalization circuit with a 12dB control range. Equalization frequency bands: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz, 15KHz, built with TI or ST TL074 operational amplifier. 2. Basic parameters: 7-band sound equalizer preamplifier gain using 4580 classic operational amplifier providing 5X amplification (14dB); input impedance is 20KΩ, output impedance is 600Ω. 3. Headphone compatibility: NE5532-based balanced headphone amplifier designed for 47 earphone driver circuits, capable of driving various headphones with adjustable output. 4. 3.5mm interface: 3.5mm input supports 4-pole plug; output connects to headset with microphone, compatible with standard mobile phone voice calls. Includes additional RCA terminal input. 5. Aluminum alloy construction: 7-band audio equalizer housed in durable aluminum alloy material offering high strength, corrosion resistance, and stable performance. Operates on DC 5V–12V power supply with dual channel audio support. Compatible with car audio systems, mobile phones, computers, game consoles, and other devices. Color: Black Material: Metal Package Contents: 1 x Headphone Amplifier Mixer Note: Light reflection and display differences may cause slight variations in color compared to the actual product. Measurement may vary by +/- 1-3cm.