We spec fuses with the idea that we want to avoid any damage due to the relatively high possibility (compared to a factory built product) that there might be an error in construction. Thus we spec them really close to the maximum startup current inrush. Sounds like what has happened in this case is that small batch variations in the charging current of the filter capacitors just stacks up such that the occasional amp needs a tiny bit higher rated fuse. I think this is the first time we have seen that with Stereomours. I do recall having a similar situation occur a few years ago some Crack amps, IIRC. Ofttimes that fuse blowing will just happen the first time, and after the caps have formed you can get away with the stock value. But for a .1 amp difference like we see here I wouldn't even worry about that, just leave that 1.6A slo-blo in there.
