Those pyramid power supplies are POS's!! Just like their stereo equipment. Way over rated and is just junk! I have one that blew for no apparent reason as well. Didn't over load it and the fast blow fuse didn't catch shizz!! They are junk and I wouldn't buy one, wouldn't take one of someone tried to give it to me!! But that is just me. Some might have great luck with them. But I think they are just plain out junk that is way over rated. Sorry if I make anyone mad. Just stating my opinions on them. The pyramid PS's that is. Have a good evening to all.