7-Band Equalizer Headphone Amplifier with 3.5mm Input, 2-Channel Audio Mixer

A 7-Band Equaliser and Headphone Amplifier in One Unit This EQ-7 unit combines a seven-band graphic equaliser with a dedicated headphone amplifier, giving you precise tonal control over your audio in a single compact device. It is designed for use with car audio systems and other line-level sources, allowing you to shape the sound to suit your music and listening preferences. The equaliser section provides control across seven frequency bands: 60Hz, 150Hz, 400Hz, 1KHz, 3KHz, 6.5KHz and 15KHz. Each band offers a control range of ±12dB, giving you the flexibility to boost or cut specific parts of the frequency spectrum. The circuit is built around a TI or TL074 operational amplifier, delivering clean and reliable signal processing. Precise Sound Shaping for Your Setup The unit also functions as a preamplifier with a gain of 5X, equivalent to 14dB, provided by the 4580 operational amplifier. This allows you to boost a weak signal before it reaches your main amplifier. The input impedance is 20K ohms, and the output impedance is 600 ohms, making it suitable for connecting to a wide range of audio equipment. A Built-In Headphone Amplifier For private listening, the integrated headphone amplifier uses the NE5532 operational amplifier in a 47-style driver circuit. This circuit is capable of driving a variety of headphones and includes an adjustable height control, so you can match the output level to your headphones and preferred listening volume. Simple Connectivity for Music and Calls The unit features a 3.5mm input interface that supports a 4-pole plug, allowing you to connect a headset with a built-in microphone. This means you can use it for normal voice calls on your mobile phone as well as for listening to music. A terminal interface is also included for additional connection options.