Arkless Electronics
Trade: Amp design and repairs.
Why you're sorry to report this, AND be in a quandAry, is beyond me, Dan. You've just discovered what I. and a few others, have known about for yonks. Bless his engineering heart, but young Arkless is wrong when he says that chassis fuses do not affect s.q. He's right on the safety risk, though (otherwise why have fuses in the first place?).
I've not had ARC stuff, so it's interesting to see that this is yet another make susceptible to this, as is my Meridian CDP, my E.A.R. valved monoblocs and all the Naim kit I've had. The jury's still out on my Lector CDP, though, so it's not a blanket endorsement. RCBOs (or possibly separate MCBs and RCDs) are very effective safety devices, especially when each is dedicated to just one piece of kit, but the chassis fuse is there for a very good reason (unfortunately).
Oh yeh..... and you would know all about LT, HT fusing, differences between fusing in the primary and secondary of a transformer, before or after bridge rectifier or even after complete PSU in split rail supplies in solid state amps then? and what the likely effect of any resistance (linear or non linear) would be in all those different areas?
It can have some effect in certain areas of certain types of amp but much smaller than that in a speaker. In most places it would have no effect.... and certainly not in a pre amp!
Go ahead and blow your amp up though.... it keeps the likes of me in beer money (try not to do a "Philpot" though )