Mike Sapone, a go-to producer for emo and pop-punk acts with big ambitions, first blew up in the late 2000s. His stellar rep rests on his work with such bands as Taking Back Sunday and Boston Manor, whose mainstream success can be credited in part to Sapone’s catchy mix of guitar crunch and sci-fi atmospherics. Yet it’s a sound that’s also attracted plenty of indie rockers, including Mansions and the fuzz-worshipping Cymbals Eat Guitars.