Thanks for your answer. Your explainations were clear. I would have another question about d.i.i. Tonight, I had a music practise and when we tried to plug the melodica in the mixer with a passive d.i.i, it didn’t work. I thought I broke the melodica’s 1/4 input when trying plugging headphones last week. However, we tried with a guitar amplifier and it worked. At my school, we also have active d.i.i. Our plan is to plug my melodica in the mixer with an active d.i.i next week. If we do that, would it break the melodica because of the power of the active d.i.i. Another of my friends told me that sending electricity in an instrument that did not required power could break the input jack. I hope my explainations were clear. English is not my first language and I don’t know a lot about mixers, sound and all of that.