The things people actually ask about the Axe-Fx III, answered in a sentence or two, with a link to the detail.
A scene is a snapshot of the whole preset — what is bypassed and which channel each block is on. A channel is a variation inside one block, and every block has four. Scenes are the song sections; channels are the four drives living in one Drive block.
No. It is driven from the front panel unless you add an FC-6 or FC-12, which connects over a single XLR cable and is a separate purchase.
Two amp and cab pairs. The FM9 also allows two; the FM3 allows one.
Input 1. It carries Fractal's Secret Sauce instrument front end; inputs 2, 3 and 4 are line level and will not sound the same.
Use a Humbuster cable from a quarter-inch output — TRS at the Axe-Fx end, TS at the amp. That wiring cancels ground-loop hum and is built into every quarter-inch output.
14 columns by 6 rows, and every slot and cable is stereo — you never build separate left and right paths.
A preset change reloads the whole grid. Build song sections as scenes inside one preset instead — scenes load nothing, so they switch seamlessly and tails carry through.
512, or 1024 on the Mark II.
Yes. Output 1's XLR and quarter-inch jacks carry the same signal simultaneously, so the desk and your amp can share one output.
Fractal's current amp modelling generation, on the Axe-Fx III, FM9 and FM3. The Axe-Fx II runs the older Ares line and cannot be updated to it.