/diy/ - Do It Yourself

>>1416797
Pic related is a simplistic class A amplifier. Let's assume that the transformer's ratio is 1:1 and that you want to feed +1A/-1A current to the speaker. Since your transistor has to remain conductive even at the negative peaks, you have to set the no-signal collector current to at least 1A, preferably somewhat higher. The collector current will then be close to 0A at the negative peaks and a bit over 2A at the positive peaks. This 1A current and the associated power dissipation does nothing productive, it's just needed to make your circuit work. This obviously hurts your efficiency.
A class B amplifier, on the other hand, draws only as much current as your load needs. A simple class B equivalent for pic related would use dual supplies with the same total voltage as the class A circuit, but drawing only +1A/-1A during the peaks. And the quiescent current / quiescent power would be ideally zero.

This was a rather hand-wavy explanation. If you want to play with math, you can replace the transformer/speaker with a resistor and calculate the total input energy vs. the output's AC component's total energy over one sine cycle.

how do i make my own headphone amplifier?
how should i modify the circuit based on the headphone i will use?

why might i choose, say, class a over b or vice versa? which would be simpler on my brain?