I don't think it will go to Alpine directly, most likely one of their authorized service centers like United Radio in Syracuse, NY if you are on the East coast.
They are ISO 9002 certified and have well trained folks, you can track your amp's progress every step of the way with their tracking system. If it is not under warranty they typically charge a flat rate fee no matter what is wrong with it. They serviced an Alpine 7949 for me a few years back and did a stellar job.