Most tuners ignore intonation theory. In equal temperament, the major third is 14 cents sharp — causing chords to beat under distortion. Dropping the B string 14 cents brings the G–B interval closer to pure intonation. This applies in open tunings too (Open E targets G# instead). The Buzz Feiten Tuning System corrects the same problem at the nut level. Three presets: Standard ET, Just 3rd, BFTS. Guitar, Bass, 12-string, Ukulele. Auto string detection, offline PWA, no login.