## Portable Headphone Amplifier Electronic Circuit Diagram

Launched by: Kylie

On: 13 Jun, 2016

Viewed:1,437 times - 2 hour, 10 minute, 15 second ago

Category:

Rating:
4
67 out of 100 based on 256 user ratings

# Portable Headphone Amplifier Circuit Based 3 Transistors

his simple headphone amplifier circuit can be directly connected to other compact devices such as CD player, Walkman, Tuners and tape recorder. In theory, the s...

# Portable Headphone Amplifier Circuit Based 3 Transistors

his simple headphone amplifier circuit can be directly connected to other compact devices such as CD player, Walkman, Tuners and tape recorder. In theory, the series of headphones amplifier circuit is able to work well on different impedances. The impedance is 32 ohm, 100, 300, 600, and 2000 ohm. The shown circuit scheme is for one channel (mono). If the stereo will be built live two series.

As shown in the figure, components B1, SW1, J1 and C3 are for both channels if stereo is to be made. The resistor value R3 has been calculated for 300 ohm impedance. If it will be used for 600 ohm impedance or higher, change the resistor value R3 to 100K. Actually Battery B1 can be replaced with power supply if possible, provided it is well regulated.

If the battery is still in use, the battery type can be replaced with rechargeble. The listed R3 values for 300 ohm and 600 ohm impedances are for 3.7 Volts. When used with batteries in a stereo system, the battery will usually drain within 20 hours.

### Portable headphone amplifier based 3 transistors parts list:

• R1 = 10K
• R2 = 100K
• R3 = 68K
• R4 = 1.5K
• R5 = 3.3K
• R6 = 330R
• R7 = 4K7
• R8 = 2.2R
• C1 = 1µF-63V
• C2 = 100µF-25V
• C3 = 470µF-25V
• Q1 = BC239C
• Q2 = BC337
• Q3 = BC327
• J1,2 = Stereo 3mm. Jack socket
• SW1 = SPST Switch
• B1 = 3V Battery (two 1.5V AA or C cells in series, but see Notes)

==============================================================

The portable headphone amplifier circuit is very easy to build because it uses only 3 transistors. The portable headphone amplifier can be directly connected to the CD player, or tape recorder.

The headphone amplifier circuit works well on headphones with impedance 32, 100, 300, 600 and 2000 ohm. Because the headphones have two speakers for stereo channels, it is recommended to make two series of the same.

If this circuit is built for stereo channel, then B1, SW1, J1 and C3 also be done with the stereo. R3 resistor value listed on the headphone amplifier circuit to the impedance of 300 ohms. If you are going to use headphones with an impedance of 600 ohms, then replace the value of R3 to 100k.

## Portable Headphone Amplifier Circuit Technical Data:

• Current drain: 35mA per channel with 32 Ohms impedance headphones. Much less with higher impedance loads
• Output voltage: Above 2V peak-to-peak on all loads
• Sensitivity: 90mV RMS input for 2V peak-to-peak output
• Frequency response: Flat from 30Hz to 20KHz
• Total harmonic distortion @ 1KHz & 10KHz: Below 0.05% on 32 to 600 Ohms load and up to 1.5V peak-to-peak output. Below 0.1% at maximum output

## Motorola Hi Fi Power Amplifier Electronic Circuit Diagram

This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like itÂ’s shown in the table (from 20 W to 80 W RMS).

• The first thing that you must do, is t...

## Amplified Ear Electronic Circuit Diagram

This circuit, connected with 32 Ohms impedance mini-earphones, can detect very remote sounds. Useful for theatre, cinema and lecture goers: every word will be clearly heard. You can also listen to ...

# How to build FET Audio Mixer

This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you ...

## 25W Mosfet Audio Amplifier Electronic Circuit Diagram

This is high fidelity, high quality 25W HiFi audio amplifier circuit delivers great audio performance. You don’t need pre amplifier circuit for this design since it can be directly connected ...

## Amplifier Timer Electronic Circuit Diagram

This circuit turns-off an amplifier or any other device when a low level audio signal fed to its input is absent for 15 minutes at least.
Pushing P1 the device is switched-on feeding any appli...

## Op Amp Microphone Preamp Electronic Circuit Diagram

A high quality microphone preamplifier using a single power supply, suitable for dynamic or electret microphones. The op-amp used can be any low noise, high performance type, e.g. NE5534,TL071, OPA...

#### Get daily update

As the fastest growing demand of circuit and wiring diagram for automotive and electronics on internet based on different uses such as electronic hobbyists, students, technicians and engineers than we decided to provide free circuit and wiring diagram base on your needed.

To find circuit and wiring diagram now a day its easy. E-learning through internet as a right place to search an exact circuit and wiring diagram of your choice and it's much fun and knowledgable. On internet you will find thousands of electronic circuit diagrams some are very good designed and some are not. So you have to modify them to make them according to your needs but some circuits are ready to make and require no changes.

There are many categories of circuit and wiring diagrams like automotive, audio circuits, radio & RF circuits, power supply circuits, light circuits, telephone circuits, timer circuits, battery charger circuits etc. There are many types of circuit and wiring diagrams some are very easy to build and some are very complicated, some are so small and some contain huge list of parts.

We provides free best quality and good designed schematic diagrams our diagrams are free to use for all electronic hobbyists, students, technicians and engineers. We also provides a full educational system to students new to electronics. If you are new to electronics you are a student or a electronic hobbyist and want to increase your knowledge in electronics or want to understand electronics in a very easy way so this is the right place for you we provide electronics beginner guide tutorials to easily understand complicated electronic theory. Our mission is to help students and professionals in their field.