I am an electronics n00b. Even more than that. I only know what I learn from school. I have a problem. And to that problem I made a solution. But I have no freaking idea how to implement the solution. Basically here is the source of my problem. I am running both linux and windows at the same time. I recently purchased a new sound card. However, though it has windows drivers, linux does not yet support the sound card. So I am thinking about using my soundcard that is built in to the motherboard. So the actual problem is, I have two soundcards and one speaker output. I need something that can detect an audio input and select which one is active and use that signal and send it to the speakers. That part I knew how to do. I learned it in class. I built up a truth table and did all this fancy smancy DeMorgan's stuff and built a circuit like I was taught. I have a circuit but I have basically no freaking clue on how to actually build it using real world stuff. Included is an image of what I have so far. Basically I have two inputs A and B. A is my preferred sound card and B is my onboard crap sound card. X is the desired output. 1 signifies an active signal and 0 signifies no signal. Here is a truth table and image. A B | X ----------------------- 0 0 | A 0 1 | B 1 0 | A 1 1 | A I built a truth expression of A or NotB. The output of this expression is to be feeded into a multiplexer that can select which to output. A and B are both inputs for the multiplexer as well. Tell me if you see any flaw in my work so far. But basically, what does a real multiplexer look like? Is it just a chip? I am guessing so. But I want my device to be a small box. So would I have to have 3 chips? One for the Not gate, One for the Multiplexer, and One for the Or gate? I guess I have to buy the inputs and outputs of the audio plug things. I am guessing I need a plastic box that this would all fit in. Would I need to build my own or is there some sort of universal box that can hold stuff? Also I need a power source, I am guessing this takes a small amount of power so how long would a bios type battery or AAA battery last? Basically, what would I have to buy? Thanks for your help.