I was wondering if anyone had any plans for something similar to the Mackie Big Knob box. I am using an old mixer to monitor off of right now, but I would like to switch over to something better, and if I can make it that would be great. It seems like I could make a box with 3 inputs that go to a master volume knob and out to the speakers passively, using switches to select which inputs and outputs are used. I need something that can split the signal so I can send it out to both the speakers and a headphone amp, and have seperate volume control of each. Other features would be neat, but that is the bare minimum that I need. Is there a project that does this already that someone can point me to? If not, what type of variable resister should I use for the volume controls, and would it be OK for me to just split the inputs to the two controls (headphone amp and speakers) without any sort of active electronics?