Not satisfied with the sound quality.

Sound quality also depends on your headphones. If you think the sound quality of the unit is limited to what you get with the dinky cheap earbuds that come with it…it’s not.  Get some decent Shure or Grado or Sennheiser or Beyerdynamic headphones and it’ll sound a lot better. 

Sound quality also depends on how the music files are ripped. If your files are 128kb they are always going to sound mediocre. 

Rip your CDs to–or get music already ripped to–at least 192kbps, a VBR (variable bit rate) above that or 320 kbps. It makes a diifference.