help bulding BJT amp

[eng.samir1]

hello everyone
am trying to design a BJT amp ...
i came out with 2 circuits and i used multisim to simulate it
this are my results


2nd circuit



my input is 50mv.

when i tried this cicuit on the bread board it didn't work ...
can any one point to me why is that??
???

 

[audioguru2]

Transistors have a wide range of current gain. Usually the voltage divider that provides base voltage has a current that is 10 times the base current of a typical transistor so it will work with a low gain or a high gain transistor. The current in your voltage dividers is very low and will not work if the transistors have a low current gain.

Since your circuit does not work then simply measure the voltage at the collector and emitter of each transistor to see if one is cutoff or saturated.

The value of the emitter bypass capacitors are so low that they increase the gain (and increase the distortion) only at high frequencies above 2.1kHz. The gain will be max at about 210kHz. Use 4.7uF for max gain at all audio frequencies.