Question: I would like to build a simple audio amplifier using transistors. I know there are IC designs specifically for the task. But i want to use transistors so i can learn how to use them for amplification.

How would I go about designing an audio amplifier from just discrete components.

Answer: 
There is nice example of transistor amplifier in popular book "Art of Electronics"
![Art of electronics (1st edition ?)](https://i.stack.imgur.com/9dVtq.jpg)
There is an easy schematic for a class A audio amplifier with a darlington pair. A darlington pair is just two transistors that square the gain of the first transistor(if you are using identical transistors). So if the first transistor's gain was 20, then the gain of the darlington pair would be 400. [This website](http://sci-toys.com/scitoys/scitoys/computers/solderless/amplifier.html) uses a darlington pair in the form of one transistor: