The RC4558 is a dual opamp. The datasheet says ieach half is electrically similar to a uA741. So you can use it in any 741 circuit.
The datasheet for the 4558 shows that each of its opamps can drive a 10k load very well and drive a 2k ohms load not good but not too badly.
It is not a stereo power amplifier. Instead it was designed to be the preamp in a record player or tape player that drives the inputs of a power amplifier.
What is the impedance of your headphones? 2k ohms or more? I doubt it because most headphones today are 32 ohms.
Impedance is resistance to an AC signal. Measure its resistance with a multimeter. Its resistance will be a little less than its impedance.and how to measure the impedance of head phone ? its an earplug actually by nokia
Impedance is resistance to an AC signal. Measure its resistance with a multimeter. Its resistance will be a little less than its impedance.
The resistance of the headphones (earplug kind) for an iphone is 33.4 ohms for each ear and it needs a little power amplifier to drive it.
Then your earphones must be the 60 years old "crystal" (piezo) kind. In the WEST, headphones are the modern "dynamic" (coil and magnet) kind.hmm i tested but maximum range of 2000k on a multimeter i got no reading . .
At those days, Nokia has been making rubber boots as far as I know. There must be a different explanation, e.g. incorrrect measurment.Then your earphones must be the 60 years old "crystal" (piezo) kind
Now try a more sensible range like 200 or 2K.hmm i tested but maximum range of 2000k on a multimeter i got no reading . .
Because the reading is very low? That is normal on such a high range.hmm i tested but maximum range of 2000k on a multimeter i got no reading . .
Finger prints on the meter probes and earphone plug cause the very low resistance to change. Your earphone are probably 16 ohms for each ear so you need a little stereo power amplifier to drive them.
I looked in Google Images for Earphones Amplifier Circuit With Opamp and found hundreds of circuits.
The circuit will work with any pair of medium power NPN/PNP transistors, let's say > 1 W.
The low current BC547 and BC557 transistors will blow up if the output of the amplifier is shorted when it is playing loudly.
I would use TIP31 and TIP32 medium power transistors that will survive.
This amplifier might produce enough loudness in earphones to deafen you so maybe you will need an attenuator resistor in series with each earphone.
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