I use the Mobile Cube for harmonica. It has a warmer tone than the Microcube. It packs quite a big punch for its size and it has lots of input possibilities (instruments, AUX and mic) and settings, including reverb, clean, overdrive, distortion, chorus, acoustic guitar, electric guitar, tone knob... You can play your backing tracks into it and play your instrument at the same time for busking. It's a little cracker and you can use it on just six AA batteries if you want to (annoyingly, you pay extra for the mains adaptor, but I just haven't bothered, as battery life is pretty good, and you can always use rechargeables). It does have a headphone socket, which mutes the sound, but, slight drawback, there's no alternative line out. A bugger if you need it, but maybe, like me, you just don't.