The production of several super bass circuits 02

(2) The subwoofer potentiometer STr
    )D circuit is shown in Figure 9-37. The operational amplifier Al and peripheral
components form a second-order Butterworth high-pass filter, which has a gain of +6dB for the ultra-low frequency band of 28 to
88Hz. The second-stage operational amplifier
A2 is a subwoofer gain amplifier, and the external potentiometer can Adjust its gain and increase +lOdBp because a feedback capacitor of 0. 018tiF is added
to each stage of the circuit .
It is in a straight-through state for frequencies above 88Hz
, that is, the entire circuit has no effect on mid- and high-frequency signals
. Therefore, the entire circuit can be connected in series between the preamplifier and the power amplifier
, and the amount of bass improvement can be changed by adjusting the potentiometer RP.
The power supply voltage is equipped with a 12V voltage regulator tube, which can be powered by ±15V ~
±36V dual power supplies to adapt to
the installation of most amplifier circuits. When using a single power supply, a bias resistor must be added, and the effect will be
good. The entire circuit together with the potentiometer
is installed on a 4. 6cm .