Just would like to know what's the difference between the two. I have saw Yamaha's YT120 (guitar) and YT250 (chromatic). The difference is quite obvious, since the YT120 only have LEDS and no digital needle, while the YT250 have digital needles. But when I saw Korg CA30 and Korg GA30, both have digital needles! I assume that we should get a Bass/Guitar tuner instead of Chromatic Tuners? Chromatic Tuners are only for other instruments, right?