Equalizer 3 band

This is mono 3 band equalizer circuit. The circuit is simple, cheap and easy to built. You should make two circuits for your stereo audio system.

Supply voltage may be anything from 6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage.

5-Band Equaliser Circuit

Above circuit is a 5-Band graphic equaliser circuit from Electronic For You Magazine, published May 2007. This equaliser uses low-cost op-amps NE5532 or LM833. Those ICs are good-quality op-amps powered by a single voltage supply are readily available in the market.

This 5-Band equaliser circuit is powered by a 12V DC regulated power supply. A well-regulated power supply using 7812 is recommended.

Download 5-Band Equaliser Circuit document from Electronic For You Magazine:
» Download Link

4 Band Audio Graphic Equaliser Circuit

This is the circuit of 4 band audio graphic equaliser. The equalizer will cut and boost the four range of audio frequency, that are:

• Low frequency: Freq. 35-680Hz
• Medium frequency: Freq. 150-3kHz
• Medium/semi high frequency: Freq. 450-8.5kHz
• High audio frequency: Freq. 750-15kHz

Circuit note: Use regulated power supply, metalfilm resistor, MKM nonpolar capacitor and tantalum bipolar capacitor for best audio quality result.

This circuit is available in PDFdocument. Download 4 Band Equalizer circuitfrom the following link:
Download Link