This thing is not amp, it is software with garbage hardware.
I bought it for my girlfriend's birthday, because a friend of hers had the Spark Mini.
Even in bluetooth mode, for mp3s, this sounds utterly dreadful, showing that the speaker is incapable of any kind of decent sound reproduction.
The sound is boomy, muffled and muddy. Sounds like it's in a shoe box.
The preset sounds are mostly extremely poor, barely usable for home playing, nothing is usable for live or studio work.
If it were my choice, I'd return it after 10 mins of use. Worst hardware I've tried in many years.