I have an older Boss TU-15, but it doesn't seem to be able to tune/read the lower 4 strings. Not sure I have the right setting, it has a drop D setting, but drop C seems to confuse it. The tuner on my M5 can do it just fine, not sure how accurate it is, but at least it doesn't get confused. However, it's a big pedal to be mostly used as a tuner right now. So how about a TC Electronic Polytune Mini v2? It mentions drop D, but I don't see drop C or B listed. Can it do it? Other tuners (pedal or clip on would be fine). I like the size of the Polytune, would be great to have something permanent on my board.