I bought a book on electronics for guitars (and basses of course) and there is a section that shows how you can hook a 6-way rotary switch to a 4 lead PU + ground and have 6 different tones. Well, I know it works, in the sense that it is possible. But is is noisy? Has anyone done this to a bass or guitar? Let's use for example a SD MM style Hum with 4 leads... has anyone tried hooking one of these up to a 6 way rotary? Also, what about running 2 PUs this way with another 6 way as a selector switch? Any sites that have details on this type of practice?