It looks like the amp comes with a universal transformer, the schematic shows the various wirings for 100/120/230/240v operation. You'd also have to reduce the mains fuse by half. Not sure of any other changes. I think at most they would be the addition or removal of some small film caps.
Send me an email with SVT 3 Pro Schematic as the subject line and I'll send it to you.
Oh yes, and you are aware that US amps must be turned upside down to operate properly in Australia, are you not?