I noticed that many mixers such as the Behringer hard wire their line inputs (without even a switch) in parallel with the mic input to the mic preamps. Yes, they do have a drop resistor but that's all. My concern is that the signal is being dropped and then amplified back up - thus adding another stage and more noise. No switch also means both a mic and a line source can be both "on" at the same time. I was thinking of adding a small switch and routing the line input to just after the mic pre. Here I am just looking for reactions and suggestions.