headphones amplifier

N

n2_b0y

New Member

• Feb 23, 2012

• #1

Hi guys.. it seems that this amplifier has low volume.. i dont know whats the problem with it.. can u help me?

View attachment 61391

tnx a lot!

 

ronsimpson

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #2

I think you are right it has low volume. There isn't much fear of hurting your ears.
What type of head phones are you using?

 

N

n2_b0y

New Member

• Feb 23, 2012

• #3

i dont actually know what kind of head phones is this but when i plug it directly to my mp3 player, it has actually good/loud sound.. is there anything wrong with the circuit?

 

ronsimpson

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #4

Your amp is running from a 3 volt supply, I think 9 volts is better.
Your amp has a 2.2k ohm resistor to limit the power to the headphones.
The amp you built applies a DC current to the headphones.

 

audioguru

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #5

The 2.2k resistor in series with the headphones reduces the volume a little for 600 ohm headphones and a lot for low impedance headphones. It is not an amplifier, it is an attenuator.
The extremely simple circuit puts DC through the headphones that is bad.

I simulated it:

 

N

n2_b0y

New Member

• Feb 23, 2012

• #6

i dont actually know what kind of head phones is this but when i plug it directly to my mp3 player, it has actually good/loud sound.. is there anything wrong with the circuit?

 

ronsimpson

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #7

It should never be used with low impedance headphones.
I think it should never be used period.

 

N

n2_b0y

New Member

• Feb 23, 2012

• #8

is this be good? where will be the output connected?

 

N

n2_b0y

New Member

• Feb 23, 2012

• #9

ronsimpson said:

It should never be used with low impedance headphones.
I think it should never be used period.

Click to expand...

what are you trying to mean?

 

N

n2_b0y

New Member

• Feb 23, 2012

• #10

audioguru said:

The 2.2k resistor in series with the headphones reduces the volume a little for 600 ohm headphones and a lot for low impedance headphones. It is not an amplifier, it is an attenuator.
The extremely simple circuit puts DC through the headphones that is bad.

I simulated it:

Click to expand...

is this be good? where will be the output connected?

 

ronsimpson

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #11

This is a bad amplifier.

 

audioguru

Well-Known Member

Most Helpful Member

• Feb 23, 2012

• #12

It is a very poor headphones amplifier.
The 32 ohm resistor R9 is one ear of 32 ohm headphones.