Everybody knows the secret to Eddies tone comes from the tobacco to filler content of his smokes as it drifts across the magnets of his pups**. When he started smoking lights, around the time of the 5150 album, his tone went to $hit, and it's never been the same since.
Yes, the real change in his tone has come from the Tobacco Industry , and it's over regulation by the U.S. Government. Any of us Southern Boys who grew up in the Tobacco belt can tell you- hand rolled (tobacco) smokes from fresh cut & dried tobacco are the ultimate for tone. The crap you buy in 7-11 is a total tone-suck.
** And this is why Brian Robertson's tone has always rocked from day 1, and does still today