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I wonder how you ever want to design electronic circuits if you don't manage to find out the essential data of the components available in your favourite electronics shop ? I learned it as a school boy.
In Europe, I would use the BD139 and BD140 medium power transistors that are packaged in a very old case.
In China, I would use the Oriental transistors.
As far as I can make out, he's not interested in learning anything, he just likes to build stuff. Different strokes for different folks.
Any of these transistor pairs should be good:
NPN / PNP
mje340 / mje350
bd139 / bd140
2sc4793 / 2sa1837
2sc3421 / 2sa1358
It is a different world over there.
I will let people there talk to each other about their problems that we don't have here.
I do not see a schematic of your earphones power amplifier.
Why did you use an input resistor value that is much too high?
Why did you connect 10 ohms in series with a low resistance earphone to the output of an opamp that cannot drive them without booster transistors?
I do not know how much negative feedback you used.
I do not know if you used a dual polarity power supply.
The rows of contacts and the many connecting wires on a breadboard are antennas that pickup mains hum that is all around you in the air. An unshielded input cable is also a mains hum antenna.
RC4558 power supply? Really?i am just applying +ve at pin7 & -ve at pin4 & rest nothing
RC4558 power supply? Really?
It seems that you know NOTHING about electronics.this one is sensing my palm & creates distortion . . well coming to main part i didn't apply any feedback , didn't connect any transistor at output . . all those things i left , please tell how to connect feedback ? should i connect output to pin3 (+) ?
There are thousands of instructions about opamps on the internet.Now what is dual polarity power supply & how to apply here ? why we need ? please explain
i am just applying +ve at pin7 & -ve at pin4 & rest nothing , just i explained what i connect & its nothing much
secondly i connect 10 meg high resistor at input because with lower values either it creates complete distortion or creates no sound
It seems that you know NOTHING about electronics.
You found and posted a pretty good amplifier but did not make it. Instead you made a mess with Everything Wrong.
There are thousands of instructions about opamps on the internet.
Manufacturer's detailed datasheets are also found on the internet.
The datasheet for the RC4558 dual opamp and for many other dual opamps shows a typical voltage gain of 300,000. Negative feedback is added with two resistors to reduce the gain to about 30. Then the distortion is also reduced a lot.
The capacitor values are not critical. C1, C2 and C3 can be up to 5 times smaller, so:all the conponents are with me now or all are easily available in nearby shops
The capacitor values are not critical. C1, C2 and C3 can be up to 5 times smaller, so:
C1: 220uF to 1000uF
C2: 0.47uF to 2.2uF
C3: 220nF to 1uF
You can use even smaller values, but there will be a bit less deep bass.
C4 and R5, near the input are not critical either. You can make C4 much smaller, or even leave out both parts altogether.
The value of C5, across the power supply is not critical either. A big value like 1000uF will help when the battery starts going flat, but aside from that you can use a much smaller cap - even 100nF is OK.
Maybe you already have all the parts you need to try the circuit.
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