@incorrigable - As I've tried to explain, this isn't something all power supplies are capable of. I worked for a manufacturer who purchased a lot of transformers and eventually ended up winding our own.
The issue is very much manufacturer/model specific. Accuphase uses the same transformer for US, Japan and UK markets. They do this with split primary windings. These transformers have multiple primary wires, not just 2. How you attach them to the terminal strip changes the voltage ratio between input and output. Essentially this requires knowledge and a Philips-head screw driver.
Luxman integrated amps do NOT do this. They use separate transformer models for Japan, the US and the UK. To convert a Luxman integrated amplifier you need a different power transformer.