i got garageband for ios on an ipone 5s. The phone and sound, mp3 player, and earbuds work fine. I got my tinnitus from them. I have tried a couple of different guitars and the input registers pretty low to about the middle of the input signal indicator. The output is so low from the earbuds it is unusable, you can just tell there is some sound coming out. I do have the monitor option selected, and have explored the output, master volume, all the controls on some of the amp. I'm using a cable that has a 1/4"guitar jack, an 1/8" jack to plug into the earbud port on the iphone and a female 1/8" to plug in the earbuds. Its not a Griffen but same thing. Any clues on how to troubleshoot this or the cable? Do I need to put a boost pedal in front of it?