Headphone amplifier circuit diagram composed of TA7376

When listening to music with headphones , especially small headphones, I always feel that the music taste is not enough, and the effect in the low frequency band is even worse. Therefore, this unit is used to enhance the low-frequency characteristics of headphones, and adopts the method of stereo inversion synthesis, coupled with the built-in simple matrix surround sound circuit, to obtain strong bass and widen the sound range in a wider range.

This unit is called Super Square Effect. This gripping power is no less powerful than live stereo sound.

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Circuit principle

The circuit of this machine can be roughly divided into the following three parts:
    1. Low-frequency enhancement circuit composed of resistors and capacitors.
    2. Use the feedback input of the power amplifier IC to form a stereo inverting synthesis circuit.
    3. Use the power amplifier IC to form the driving circuit of the headphones.

The resistance and capacitance between the input ICs enhances the low-frequency characteristics. Because of the addition of a potentiometer, the enhancement amount of the low-frequency part can be continuously adjusted between 0 and 10 times.

The stereo inverting synthesis circuit IC consists of 0.47UF and 50K potentiometers after the DC coupling capacitors at pin 2 and pin 8. In this circuit, the left and right treble parts of the stereo square effect component are inverted respectively and then synthesized to enhance the effect.

Propelling Headphones with Toshiba TA7376P. This kind of IC has two built-in channels, few external components, and can work at low voltage. When the load impedance is low, attractive low-frequency sounds can be reproduced.

If the power supply is changed to 5# batteries, four of them are connected in series and the voltage is 6V, which can directly drive high-output speakers. If you increase the three 200UF/10V capacitors to about 1000UF, you can get better results.

Component selection

All components are nothing special. The resistors are all 1/8W. The 0.1UF and 0.47UF capacitors use monolithic capacitors, and the others use electrolytic capacitors. Among the potentiometers, 20K is a double-connected potentiometer, and 50K is a potentiometer with a switch. The plug is a stereo plug.

make

It's so easy to make that even a beginner can make it in a day. Pay attention to the pins of the IC and the polarity of the electrolytic capacitor.

The wiring of the potentiometer is messy, don't make a mistake. If there are no wiring errors and poor welding, success will be immediate.

Plug in stereo headphones or regular headphones , insert the battery, and turn on the switch. If the two knobs work well together, you can get extremely touching effects when listening to music. Appropriate adjustments according to the music and sound source you are listening to are the key points in using this unit.

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Needless to say, better results will be obtained when connected to small speakers, TVs, and CDs .

Note: In the circuit schematic diagram, W1 is a double potentiometer for bass enhancement, and W2 is for adjusting the reverberation effect. In the printed circuit board diagram, A1 and A2 are the left and right channel inputs. Potentiometers W1 and W2 are both fixed on the edge of the box, where W2 is a potentiometer with a switch.