I have a carvin bx500 head that I really like. I can always get a good tone out of it whether I'm using my upright or electric its really a pretty good doubling amp. I have two things I'd like done to it, first and more easily, I'd like to add a pre/post switch to the direct out. It seems weird that the amp wouldn't have this feature, but it doesn't. Second since I'm using the dpa 4099b mic for upright I have to bring an extra preamp that can supply phantom power to the mic. It would be amazing if there were a way to put a combo 1/4" / XLR jack on the front of the amp and build in the phantom power supply with a switch to turn it off. There's plenty of physical room inside the amp so I guess its just a matter of if it will work from an engineering standpoint. Does anyone know of someone who could take this on? I'm in michigan but I could mail the amp out I suppose if there were someone who could do it. Thanks, Jon PS Carvin said they don't do that kind of stuff themselves, but they sent me schematics if I found someone that would.