You can order those size fuses from most all the big electronic parts stores or maybe even you local electronic parts store or even Radio Shack. If it was a slow blow .5A you can use a 1A fast blow, but it is better to stay within the design. I have tried the HiFi Tuning Line fuses (very expensive for a fuse) and did not notice any change in sound. Might have been one but it is too small to tell for me.
