Are Basic Electronics Enough to Build a Speaker Amplifier?

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weitao
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How to build this amplifier ? Need what component!
 
If you want to play around with transistors you can build a class AB amplifier:

Circuit schematic of a class AB push-pull transistor output stage with +V and -V supply rails, two diodes labelled 1.4 volts biasing the bases, an input signal node, and an 8 Ω speaker at the output.


or you could build a simple amplifier with a chip LM386:

Circuit schematic of an LM386 audio amplifier with a 10k potentiometer at the VIN input, a 10 µF capacitor across pins 1 and 8, a bypass capacitor on pin 7, and a 250 µF output capacitor feeding a speaker through a 0.05 µF and 10 ohm Zobel network.
 
weitao said:
What transistor? NPN or PNP?

what's first circuit contains one of each, right?
 
Ya ! Which transistor? And how to adjust the base? And second circuit, what is mean by "by pass"?
 
I don't think this forum is the place to be looking for advice and circuits to build when a person can't tell the difference between an NPN and a PNP transistor from looking at the schematic. There are several other things omitted from the schematic that what posted as well. Not that it isn't a workable circuit, but it is not a turnkey solution. It is a place to start.
 
weitao said:
Ya ! Which transistor? And how to adjust the base? And second circuit, what is mean by "by pass"?

I agree with supernova -- you are not ready to make an audio amplifier from scratch.

But, you may be ready and interested in building an audio amplifier kit. That's a great way to learn how to build electronic circuits, and each kit generally comes with tutorial materials to help you understand how it works.

Have a look at these kits:

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLL_enUS301US302&q=audio+amp+kit

You can also just look at the electronics store nearest you (Radio Shack, Frys Electronics, etc.) at their kits.
 
Averagesupernova said:
I don't think this forum is the place to be looking for advice and circuits to build when a person can't tell the difference between an NPN and a PNP transistor from looking at the schematic. There are several other things omitted from the schematic that what posted as well. Not that it isn't a workable circuit, but it is not a turnkey solution. It is a place to start.

Not me can't see the difference but have PNP and NPN transitor in first diagram and I just learn basic electronic only!