I had to stop and think why the Pioneer shut down with the M5s before I could hear any distortion as opposed to the M50 where distortion is evident and it doesn't shut down. The protection in the Pioneer must be current-sensing. The M5 needs a lot of current compared to the M50. The protection kicks in as the current rises before distortion sets in. The M50 on the other hand needs less current as the volume is turned up. However, as the volume is turned up, the Pioneer gets into its non-linear operating zone causing distortion.
One of the things I like about the ADA is its protection philosophy. It will self-protect before you hear any distortion. When it self-protects, you know you need to change something in your set-up.
