3 Band graphic equalizer
Notes
Using a single op-amp this easy to make equalizer offers three ranges, low frequency,mid frequency,and high. With component values
shown there is approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz. Supply voltage may be anything from
6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage.