The odd, crackling audio which has bedeviled some SAM460ex and AmigaOne 500 owners has finally had its root cause identified: a missing resistor on some boards. According to Acube Systems a particular board resistor which serves as a clock select for the on-board AC97 codec is missing for some boards but not others.
Acube is making a special version of the sound driver available which should help mitigate -- but not entirely eliminate -- the issue. The ideal solution is to determine if the board is missing the resistor in question, and if so, contact your dealer for servicing. Users encountering 'hissing' or 'staticky' audio should click the link below for more information on how to determine if their boards are effected and next steps to take.