I highly doubt its a lack of power issue. An amp thermals because it reaches a temperature level that makes the thermal circuit trigger. That means its getting too hot.
It has already been mentioned once that Ray can get the 2250 to shut down in one hour. Another user mentioned he has got his amp to shut down. Now here is someone else stating their amp shut off in 40 minutes with no ventilation issues. To me that is fast. As i have stated before, the modified DPS500 will stay running at max level for around three hours and that amp wasn't even designed to run that hard.
None of it even makes sense to me. For an amp that is supposed to be extremely over built with parts running at a fraction of their capabilities, you would think the amp wouldn't break a sweat to make rated power.
I haven't had this issue yet. However, my amps have had other issues so I haven't had the 2250 installed long enough to even get to the point of tuning.
Clearly, if these users are running their amps into clipping for long periods, that can have an affect on the amp going into thermal quicker....as stated previously. However, "SQ Audio" has stated previously that he runs his amps at minimum gain.