Fuses for a Bryston 4B ST

A friend suggested upgrading the fuses in my modified Maggie 1.6s and my Bryston 4B ST with silver filament fuses. I figured while I was at it, I'd replace the one in my B&K 307 AVR. I currently use the B&Ks Pre amp section for stereo listening with the Bryston. Does anyone know what size fuse the Bryston requires? Also, The B&K requires a 12 amp fuse but all I can seem to find in the silver filament variety is 12.5 amp. TIA