This circuit should be placed between the signal source and the input of a recorder or amplifier. The amplifiers may be of the type 741 with symmetrical power source and shielded signal cables. The equalization of frequency bands are indicated next to each block. In this type equalizer, the attenuation and reinforcement of each frequency band can be adjusted separately. In this circuit specifically we have 5 channels, whose frequencies are indicated next to each adjustment pot, which should be linear. Operational are simple type 741, but can be used double versions. The power supply must be symmetrical 6 + 6 + 15 V to 15 V with excellent filtering. A source of about 100 mA is sufficient to power the circuit since its consumption is very low. For a stereo system, they must be installed two units as this, one for each channel. The power supply can be only one.
