Go to this link: http://www.k6xx.com/ft817/ft817_am.pdf
They're all software driven! I just picked up one of these lovlies and am trying to get a PW contact or two. From what the above URL states, it's real easy to get your audio to sound better. AM modulation is only about 50 percent with the stock (1.5W) carrier setting. Bring the carrier down to about 1W (187-190 on menu 69) and it's supposed to hit 100 percent positive peaks and sound better!
I'm skeptical, but plan to try it with my rig. If you hear a Pissweak and hyellowy AM station on the air; it'll probably be me on my FT-817 at 1W.
Joe Cro N3IBX