I want to make a line level unit that I can mount within a rack space and use it to process recorded audio when it needs a little something or other. I'm going to have the unit split the signal into three frequency bands bass, mids, highs. Then I might process each section differently and then they will get combined at some later point in the circuit to be run into some kind of harmonic saturator to add some umph which I haven't decided on yet. I need some advice. -Since the input is line level, you shouldn't need an input buffer, but considering that there will be three passive taps from the same signal, I think it would be better to have a buffer just so you don't cause too much loading on the input signal, right? -What sort of resistor values should I use for the signal splits so each filter doesn't load down the next and cause a mess of unintentional cutoff frequencies and other problems? Maybe I need a different topology altogether? Active bandpasses? -Any practicality in using an input transformer in the unit, like those classic mic preamp designs that sounded great and used input transformers? -How should the signals be combined? It's easy enough to combine two signals and have them be variable a-la Big Muff tone stack, but the presence of the third signal complicates the design greatly. -Any suggestions for a mild but flavorful harmonic saturator circuit? Vintage and/or tape sounding would be desired. I'm thinking two color gain stages cascaded and installed in a blend circuit.