The main differences are that the 583 has a modulation wheel and an input for an optional volume pedal whereas the 483 doesn't. There may be additional voices on the 583 that the 483 doesn't have as well. I have the 583 which I use for gigs outside of my home and love it!! Other than these differences, I don't know for sure what others there may be. I'm sure others will chime in with additional information. I've only had my 583 for a few weeks and am just getting familiarized with it's myriad of functions!! The organ voices are super nice as are the others!!