NOW FOR A MAJOR ANOUNCEMENT. ALL OF NORTH AMERICA IS WIRED FOR 120 and 240 VOLTS.
Absolutely not true, not even true for residential service.
Sorry, but according to Wikipedia, he's correct for the US part of NA. Can't speak for Canada or Mexico.http://en.wikipedia.org/wiki/Electrical_wiring_in_North_America
NOPE! According to your Wikipedia link he's still wrong, even for USA only.
While most of the USA has 120/240v, nearly all of NY City (con Edison) and a few other areas have 120/208v wye as the standard residential service.
Canada has 120/240V and Mexico has 127/254v.
So all of North America is not wired for 120/240v.
When operating an amplifier in NYC it would be wise to CHECK YOUR LINE VOLTAGE and if it is not 240v then you should change the transformer taps for the proper line voltage, which is likely to be 208v in NYC and a few other places.