Graphic Equaliser

This equaliser is designed as a preamp suitable for musical instruments - guitar, bass and keyboard in particular. Unlike most conventional graphic equalisers, each slider ranges from fully off to fully on, and not the more conventional +/-12dB or so that is normally available. As a result, there is no flat setting (other than all off!). This graphic is designed to be used to create a sound, and is not suitable for hi-fi. It may be used as an add-on unit to existing instrument amp preamps, tone controls, etc. The flexibility is extraordinary, allowing a hollow "single frequency" type sound, right through to almost any tonal variant imaginable. This is the first of several projects based on the multiple-feedback bandpass filter described in Project 63, it can be made with as many (or as few) filter sections as you want.

Source Circuit:

5 band graphic equalizer using a single IC/chip

This circuit uses a single chip, IC BA3812L for realizing a 5 band graphic equalizer for use in hi-fi audio systems.The BA3812L is a five-point graphic equalizer that has all the required functions integrated onto one IC. The IC is comprised of the five tone control circuits and input and output buffer amplifiers. The BA3812L features low distortion, low noise, and wide dynamic range, and is an ideal choice for Hi-Fi stereo applica-tions. It also has a wide operating voltage range (3.5V to 16V), which means that it can be adapted for use with most types of stereo equipment.

Source circuit

5 Channels Graphic Equaliser by LA3600

This circuit 5 Channels 2 Octave Graphic Equaliser,easy to make equalizer,
because using IC LA3600 (easy to use)
Cut at frequencies of 50Hz, 200HZ,800Hz,3.2kHz and 10kHz.
Supply voltage may be anything from +12V.

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5 Channels Graphic Equaliser by LA3600

5 Channels 2 Octave Graphic Equaliser by 4558

This circuit 5 Channels 2 Octave Graphic Equaliser,easy to make equalizer,
because using IC 4558 or 1458 or LF353 (nice)
Cut at frequencies of 50Hz, 200HZ,800Hz,3.2kHz and 12kHz.
Supply voltage may be anything from -15V GND -15V for IC 4558.

View Circuit 5 Channels 2 Octave Graphic Equaliser by 4558 with PCB