Line 6 Sonic Port Channel Audio Interface Connect guitars, basses and stereo audio sources Plug in headphones, powered monitors or a guitar amp Compatible with GarageBand, Jammit and other apps Track keyboards, mixers, CD players and other iOS devices using the 1/8 stereo line input. Plug in your favorite headphones and hear your audio in stunning clarity. You can even connect powered studio monitors via the 1/4 mono/stereo guitar/line-level output.