First, you need to recalibrate the A440hz based tuners to A444hz which gives us a C of 528.008. The 444Hz is, close enough, the correct “A” pitch tuning using the Korg Chromatic tuner. If you set this Korg tuner to 444Hz (instead of 440Hz), then the tuner will guide you tuning every string (EADGBE) of the guitar. This is the simplest way to tune your guitar as A=444Hz closely approximates C(5) at 528Hz. You do not want to tune to an A flat. You want to go a little sharp, but not quite a half tone.