The SYBA SD-DAC63016 Tri-Tone Control Pre-Amp with built in headphone amplifier is different from many audiophile designs for its unique 3-band "Tri Tone" equalizer while most of the Hifi equipment has forgotten for many years. The Tone Control allows the audiences to master their song back to ?Original? even they are playing with a lower quality MP3 files on a middle-end earphone, or they might enhance different parts of frequency range; high tones (Treble), mid-range (Middle), low frequency (Bass), in order to suit their personal taste for different kinds of music