"classes A and AB work by making output transistors conduct more or less current depending on the input signal. The scheme works very well, but it produces a lo

"classes A and AB work by making output transistors conduct more or less current depending on the input signal. The scheme works very well, but it produces a lot of unwanted heat." This is a white wash.. Class A gives you 100% of the original signal, Class B and onwards represent an ever degrading of the original signal. If you are interested in quality of the signal you don't want anything to do with a Class D amplifier.