MP3 - The problem isn't the processing or kHz, it's the bit depth. You really need more than 8 bits to avoid aliasing distorsion and crackle-noise for any song that isn't heavily produced pop. Anything that is quiet or subtle somewhere you will hear noise instead of the quiet or subtle. Every 's' in a song will be a lisp and every crash cymbal in a metal song will sound like a crap cymbal.
Thought about MP3 for my A600 Portable (which soon will be faster
) and considered just plopping a normal MP3 player in it and giving it power and a switch to switch Amiga/mp3 to audio output. To have music while coding on demoparties. 0% CPU load