Ok so I am a little behind....I just got my first iphone. I am going to make a guitar input impedance matcher for the iphone. What feature would you like in one? I am thinking: IPHONE in(1/8" 4 COND) GTR In jack (1/4" Mono) Amp Out Jack(1/4" mono) Headphone out (1/8" 4 COND) DI out (1/4" balanced) I am planning on using 4.5v rails with 3 AAA batteries. I will have a simple JFET amp or opamp based circuit to do the attenuation. Anyone interested?