Hello Rottenclam,
1 - Very interesting moniker ;--)
2 - I cannot see a big deal in one-time Variac problem. Sorry.
3 I take exception with hum problem. Its not easy to fix. Since you sent your amp to manufacturer who was not able to help you then ground loop originated OUTSIDE of the amp.
You are not alone. I had to sell my Plinius SA-102 amp because I also could not fix hum in it or with it nor Vincent, their distributor and I also sent to him and amp and even preamp.
5 In 2005 there some very, very, very tragic events started in Joule-Electra family which may or may not contribute to less attention you deserved or you believe you deserved - whatever, I am giving you benefit of the doubt. Its not my role to discuss these tragic events in this or any other public forum but I have to respond to some "rotten" (pun intended ;--) audiophile who does not understand that ground loop by definition is caused by difference in non-equal "ground" voltage in two different parts (but it has been excluded) or two different components - one of which is obviously not Joule-Electra!
4 - I see no problem at all in blowing fuses even two times(!). This why fuses for. To blow themselves and protect your equipment. Its pure whining
I never saw or spoke with Jud Barber (I dealt with Simon) and I have no personal financial benefit - however, listening to the magic, truly MAGIC sound his equipment re-produce I cannot think of him anything but great (industrial) artist. Speaking with Simon about his experience from inside with the equipment failures and reading this and other audio forums writings - I can see that as the rule J-E equipment is much more reliable then most.
My hat off to Jud Barber.
The End.