The example circuit shown for SimpleAudioPlayer requires an amplifier circuit (see http://arduino.cc/en/Tutorial/SimpleAudioPlayer
). The page gives warnings about DAC damage and there are a good few reports here on the forum -- this is all good information!
I don't really understand the DAC and how it gets damaged by attaching a speaker -- would it be damaged by attaching headphones?
How about attaching a little amplified MP3 player type speaker?
What additional circuit would be required to make the DAC output happy and able to drive "line-level" audio through, say, a 3.5mm stereo headphone socket?