I am looking for the best small portable amp to plug my ETY-4's. I want to listen to hot music during long flights. Sugestions any one? Thanks

I'm new to this forum. By reading all the threads I was able to decide on Ety's. I love their sound. I feel they faithfully reproduce the original sound. After using them for som weeks now, I have one comnplaint, and maybe I can get some help here: When I move--like walking around-- I can here...