why would u wanna connect ur guitar to ur mfx to ur amp then to ur headphone? it would sound way better to just connect from ur mfx straight to ur headphone.....especially if ur mfx has amp modeling....the gt8 has amp modeling, POD has amp modeling....i use headphones too since my neighbour complaints.....but sometimes i just have to blast my amp and rock my sox off.......hhahahahaha \m/