The first impression for every user after unboxing that the power button is totally unreliable and cheap quality. Seemingly doesn´t want to power up. Then after 8-10 seconds of continuous pushing it lights up in the end. The same goes for switching it off. Something unguessable, something totally annoying. The other knobs show up a fading green light for the parameter setting, just like a disco device for kids. You never know an exact measure about a given parameter, like volume. Absolutely not recommended for professional usage! The specs describe over 100W output, but in reality at a gig it hardly could come over the acoustic drum´s volume.
JBL usually make quality, but not in this case. My worst purchase ever! Unforunately, the time has gone for sending it back, otherways I would do that immediately.