In response to a member request, Mica posted this picture, drawn by Ron, showing how to rewire the transformer to change the voltage on a DS-5.
(https://club.alembicguitars.com/Images/16271/21592.jpg)
The original thread is here (https://club.alembicguitars.com/index.php?topic=2122).
NOTE: If you have a older Stancor TP-2 transformer, it cannot be rewired and you will need to purchase a new transformer.