My PF500 was great, until it packed up whilst using it on less than half volume. Set to ampeg's own recommended setting's. Ended up finishing the gig by boosting the output from my sansamp. Was gutted to send it back, traded it in with manson's (as the couldn't find a fault with it) for a MB500. But in the end i traded the MB for a ashdown touring combo, just because i knew if it went wrong i could get it fixed. I'd rather have something heavier and reliable, the ashdown+sansamp gives near enough the same sound as my svt head. That's good enough for me.