Organize and Share your Electronics the way you want. Sign-Up for a free account now. It takes only 30 seconds!

Headphone Amplifier

Headphone Amplifier

This amplifier may also be suitable for other computer games machines, although the audio-video connectors will be different. You will have to work out the necessary connections yourself.
Circuit Operation

The complete circuit diagram is shown in figure 1. Only the left amplifier channel is shown, the right channel is identical with component references starting from 101.

Some of you may be wondering why I didn’t use a dual power amplifier IC. The simple answer is that the unit was built using bits from my “junk box” – which contained plenty of op-amps and transistors, but no power amp chips! Two single op-amps were used in preference to one dual device because this simplifies the board layout.

R1, C1 and VR1 form a simple top-cut tone control. I had not originally planned to use any form of tone correction, but the sound through a pair of good quality headphones was found to be slightly fuzzy due to the audio signals being derived by digital methods. The tone control allows this effect to be minimized, although there is an inevitable reduction in the higher frequencies. C2 together with the track of VR2 causes the lower frequencies to be rolled off gently below about 30Hz.

The remainder of the amplifier is a standard non-inverting op-amp circuit with the addition of a class B push-pull output stage. The transistors TR1 and TR2 are held close to the point of conduction by R4 to R7. Cross-over distortion is removed by the use of a considerable amount of negative feedback (R10 and R3). This arrangement works well with a low gain low power amplifier such as this.

C3 and C4 gives additional negative feedback at high frequencies (above the audio range) to ensure stability. R8 and R9 limit the output current to a reasonable level if the output is short circuited.

The overall gain of the unit with the volume control at maximum is approximately unity. Obviously this is insufficient to drive the circuit into clipping, but gives more than adequate volume from the headphones. If you like having your ears blasted you could increase the values of R10 and R110 to 33K or even 47K – but I wouldn’t recommend this unless you want to risk damaging your hearing!

The power supply is a conventional full wave split rail arrangement. This is not regulated due to the low current consumption of the amplifier. A 100mA transformer is adequate.

Visit Here for more.







 

More Articles to Read

Peeqo is a desktop bot that communicates through GIFs
Peeqo is a desktop bot that communicates through GIFs
Using a Programmable Input Multiplier to Minimize Integer Boundary Spurs
Using a Programmable Input Multiplier to Minimize Integer Boundary Spurs
Serial seven segment LED display shield
Serial seven segment LED display shield
G-code controlled drawing plotter
G-code controlled drawing plotter
An Arduino round word clock
An Arduino round word clock
The Sandwich-o-Matic will make your lunch automatically
The Sandwich-o-Matic will make your lunch automatically
Scalar Network Analyser Jr
Scalar Network Analyser Jr
An Arduino-controlled automated whiskey distillery
An Arduino-controlled automated whiskey distillery
The Rex800 looks like a dinosaur Terminator
The Rex800 looks like a dinosaur Terminator
Home Environment Monitor
Home Environment Monitor
Understanding the Operation of the Frequency Synthesizer in Maxim’s RF Transceivers
Understanding the Operation of the Frequency Synthesizer in Maxim’s RF Transceivers
App note: EPIC: Electro-Pyrotechnic Initiator Chip Resistor
App note: EPIC: Electro-Pyrotechnic Initiator Chip Resistor
Noisy ESP8266
Noisy ESP8266
App note: Noise analysis for high-speed op amps
App note: Noise analysis for high-speed op amps
Skill Sunday: Arrays
Skill Sunday: Arrays
App note: Infrared remote control implementation with MSP430FR4xx
App note: Infrared remote control implementation with MSP430FR4xx
Gesture Controlled Smart Home
Gesture Controlled Smart Home
Design for a Wideband, Differential Transimpedance DAC Output
Design for a Wideband, Differential Transimpedance DAC Output
Wrist thrusters let you fly through the water effortlessly
Wrist thrusters let you fly through the water effortlessly
Bertan/Spellman 225-20R HV power supply teardown
Bertan/Spellman 225-20R HV power supply teardown

Top


Shares