blowing 3.6 magnepan fuse

i just recently moved up from 1.6 to 3.6 magnepans, ikeep blowing the 4 amp mid fuse?? have the same setup with the 1.6(audio research pre amp, parasound 3500 amp,jlti pre phono,rega p3 turntable,and taralabs bi-wired to the speakers..any ideas out there?? maybe i hooked something up wrong...thnx