Lepai Lp-s60 4 X 25w Desktop Amplifier with Remote/usb/mp3/sd/fm
Can't go wrong with the price.  Loud enough to fill a room with sound with just two speakers connected.  If some music appear low in sound, it is most likely how it was recorded. i.e. low volume or low bit rate.  Some mp3's are better quality than others depending on copy.  Equalizing automatic sound levels throughout various albums would ensure same levels.  Non of this has to do with AMP quality or output but more with music being used and how it was ripped.  LOVE THE LITTLE AMP.  One thing that would be 