maybe u got some of the purple stuff in the alt...............
like that guy said. maybe ur regulator...... i mean when u r revvin ur engin it makes the alt put out more current......... so maybe ur regulator is puttin to many volts to ur whole car and could eventually fuck up ur main electrical system..
i would start by testing ur voltage at all batt(s) with a dmm and checking the voltage at ur amp. could be the problem