Planar Speaker Asylum: RE: What causes the fuse to blow on Magnepan 2.7 q.r's by neolith

Is it blowing just on one speaker or both involved? I biamp ST-500's into my IIIa's and don't use fuses. Never have had a problem. Since the amps are rated at 250W into 8 ohms and 550 into 4, I seriously doubt that they are clipping and I never heard anyone complain about too much power with Maggies.
If it's just one speaker, try swapping amps and see if the problem follows the amp and if so, it's probably the amp that has a problem and you should call EJ Sarmento at W4S. If the same speaker fuse blows then try swapping speakers, if the problem follows the speaker then there's your problem. Finally swap the output cables from the pre-amp/source and again if the problem switches then you have a problem with one channel on the pre. You'll need to run out to RS and get some fuses :).