Heya gerry. Sucks about the exploding converter, and sadly, if it has actually exploded, changes are it'll be too hard to repair. If it's actually blown, it means that a component has basically burnt up from excessive current/voltage running through it, and repairing it may be impossible. It's definately a pain that we have to go through so much effort to get a product working for us, but i guess that is the price we pay for the discount we got by buying overseas.
In answer to your two question: 1) You could get an electrician to have a look at it, but it may be completely beyond repair.
2) I believe there are people who get bu fine using the US power supplies. I know for sure that people who have attempted to create there own power adaptors have had issues. I for example, had a transformer made for me last week, which i plugged into my Pod X3 and proceeded to blow it up (smoke and burning smells came out). Luckily, my father is an electrical engineer, and he had a friend take it apart and fix it for me (which i guess voids the warranty that line 6 won't provide me with anyways), and he discovered something very interesting. The adaptor that comes with the Pod X3 from the U.S. is a 120->9v AC adaptor, which requires at least 2A of current. However, the first part of the X3's internal circuitry was a Rectifier, which converted the current into DC anyways. He fixed the damaged components for me, and my Pod now full functions on a 14v DC power adaptor that used to be use for a laptop.
I don't know if the same applies for the power source of your amp, but it may be worth finding out what power supply it is using, versus what it actually requires. 1 quick question: the US converter you used, was it a Transformer, or just a straight plug?
