...a slap for anyone who suggests tin foil or a nail I went to get some spare fuses for my amps the other day and I couldn't get a particular one: a slo-blow 500mA fuse for the H.T. on my early 1970's Selmer Treble'n'Bass 50. Can I use a non slo-blow fuse instead? If so what value would be OK? Out of interest, why would this one need to be slo-blow anyway? If something nasty happens in the H.T. wouldn't it be better for the fuse to go 'pop' straight away?