I'm trying to add a speaker to an RPi project, and from what I've read, the RPi's built-in headphone jack is nearly useless for driving even tiny headphone speakers.
What is a good audio amplifier to use to power a fairly small 8ohm 0.5W speaker from the RPi's headphone jack? Can it be something as simple as a mosfet switch, with the gate connected to the headphone jack's signal pin? Or do I need to use something more sophisticated like the circuit outlined here?
I don't have a lot of room in my project, so I can't use a generic off-the-shelf powered speaker. I can fabricate simple circuits myself, but I don't have a lot of resources or time to debug complex circuits, so I need something super simple.