Stereo Headphone Amplifier Circuit using TL072

Overview

In today’s tutorial, we are going to make a “Stereo Headphone Amplifier Circuit” using TL072 IC.

The designated purpose of this circuit is just one among numerous potential applications. Besides its primary role as a headphone amplifier, the circuit is adaptable for various scenarios requiring a low-power amplifier with a broad bandwidth. Its core design utilizes an operational amplifier (opamp), augmented by a pair of transistors to amplify its output current.

For bias diodes, it is advisable to use 1N914 or equivalents, as power diodes are not suitable due to their excessively low forward voltage. Using power diodes may lead to distortion in the crossover region, occurring when one transistor switches off while the other switches on.

Stereo Headphone Amplifier

A stereo headphone amplifier is an electronic device designed to amplify audio signals from a stereo source, such as a music player or a computer, and deliver the amplified signals to a pair of headphones.

Hardware Components

To make a stereo headphone amplifier, you’ll need the following hardware components to get started:

S.no	Components	Value	Qty
1	IC	IC1 = TL072	1
2	Transistors	Q1 = BC338 Q2 = BC328	1 1
3	Capacitors	C1 = 0.27uF C2 = 10uF-35V C3 = 5pF C4 = 100nF-63V C5 = 100nF-63V	1 1 1 1 1
4	Resistors	P1 = 50K R1 = 56K R2 = 22K R3 = 330K R4 = 10K R5 = 10K R6 = 33R R7 = 33R R8 = 68R	1 1 1 1 1 1 1 1 1
5	Diode’s	D1 = 1N914 D2 = 1N914
6	Audio Jacks	J1 = Audio Input Socket J2 = Stereo Headphone Socket	1 1

Schematic

Specifications

• Output level: 90mR (max) into 8W headphones
• Input sensitivity: 0.83V RMS for full power
• Frequency response: 0.5dB down at 30Hz and 20kHz
• Signal-to-noise ratio: -95dB unweighted (20Hz to 20kHz) with respect to 500mV input signal
• Separation between channels: -50dB between 20Hz and 10kHz

Conclusion

By amplifying audio signals from stereo sources and driving headphones efficiently, these amplifiers contribute significantly to a rich and enjoyable listening experience. Their versatility and ability to maintain audio fidelity make stereo headphone amplifiers indispensable tools in various settings, from personal entertainment to professional audio production.