I've gotten hold of an iPhone 4 to make use of the Voice Synth app many people are using as a voice changer and it works great in repeat mode, however I get a bad feedback loop whenever I set it to live mode going through my Aker amp. I'm pretty sure it's feedback as it's only a problem through the amp; using headphones instead yields good results but obviously as voice changer, we want other people to hear what we sound like. It makes sense' the mic picks up the sound from the amp speaker and plays it through on an unending loud loop, but as others have used amps in their setup (Deathproof, Jendor), I'm wondering how everyone else does it?
I'm using the Startech Y splitter which has issues with iPhones, but it's not causing this problem as I can use it with headphones no problem. It doesn't matter how far away I place the mic either, I added an extension cable and put the amp on the other side of the room to the mic and it still caused feedback as soon as I spoke. The volume on the Aker isn't the issue either as I get the problem even at low but audible volume.