Help with amplifying sounds

I'm having a problem with sound amplifying and later with feeding this sound to my computer. First of all I tried to find the most basic transistor amplifier possible (to understand the concept), the simplest thing I've found is this simple amplifier scheme (if you have a simpler scheme or a tutorial please let me know).

I've implemented this amplifier with single NPN transistor. When I plug in a mic it amplifies the sound sort of (only around certain frequencies I believe), but when I plug in an audio output, it wont react.

Any ideas what might not be working? And does anyone have an amplifier tutorial with some basic relevant math in it?


edit: spelling

I don't have a solution to the problem you're having with your schematic, but I am working on the same thing as you are (amplifying the sound of a small mic) and here's what I've got so far.

Whatever you do, don't use this scheme as it simply doesn't work. It is well explained though, so you might be able to use it as reference.

Instead have a look at this thread. The scheme this guy uses looks very promising and I'm actually gonna try a variation on it myself this monday. Now it may not be the simplest scheme out there, but I think it might just be the simplest scheme that will actually work ;)

whatever you do, please let me know if you get it working!

Thanks for the reply! I've looked at the schemes you have provided, they seem to use ICs for the amplification process, while I was looking to apply a scheme that works solely with transistors.

I'm going to visit my parts store tomorrow, I'll ask him about those circuit thingies though, maybe I'll go this way also.

Will keep you uupdated :D