3.5mm Interface with Microphone Support Equipped with a standard 3.5mm input interface that supports a 4pole plug. Allows direct connection to headsets with builtin microphones for clear and reliable mobile phone voice calls. Includes terminal connection capability for added versatility. Precise 7Band Equalization Control Professionalgrade 7band equalization circuit with a control range of ±12dB. Adjustable frequency bands: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz, and 15KHz. Uses quality TI or TL074 components for consistent and accurate sound shaping. Performance Preamplifier Features a 7band sound equalizer with a preamplifier gain using the classic 4580 operational amplifier. Provides 5X amplification (14dB) for a strong, dynamic output signal. Input impedance: 20K ohms. Output impedance: 600 ohms, ensuring stable performance with a wide range of audio equipment. Versatile Earphone Amplifier NE5532based balanced earphone amplifier integrated with the 47 earphone driver circuit. Capable of driving various headphone types with adjustable height control. Delivers clean, powerful audio output suitable for professional and consumer use. Practical Applications 1. Ideal for musicians, sound engineers, and audio enthusiasts who need fine control over sound frequencies across seven bands. 2. for mobile phone users who want to make calls using quality headsets with integrated microphones, while benefiting from strong audio amplification. 3. Suitable for home studios, live audio setups, and listening environments that require precise equalization and reliable headphone driving capability. This product combines precise sound control, robust amplification, and flexible connectivity, making it a dependable choice for professional and everyday audio applications.