i hope this is the right forum for this thread. if not, feel free to move it. anyway, i bought an intellitouch pt10 clip-on tuner for my basses and my acoustic guitars. it was recommended to me by the guy in guitar center. on the screen, it says A=440, and there's a button that when pressed it changes it from 4=440 all the way up to A=450, and it goes down to A=430. i understand that A=440 is what to keep it on for standard tuning (or so i was told) but what should it be on to accurately tune my guitars down? i hope this makes sense, lol. thanks