Quote Originally Posted by ackers01 View Post
The enlarger head currently has an Australian-style mains plug marked 10A 120V. Is this AC or DC? The bulb is 12V 100W. How does this square with a 120 volt system?

Any help/information/encouragement for this relative novice will be greatly appreciated.
Only having a C7700 manual here, there is precious little information. Quoting from the manual:

Light source: 12V 100W Quarts Halogen Lamp w/dichroic mirror

Power supply: Input: 100/240V 50/60Hz
Output: 12V 100VA
The original wiring and bulb holder is not designed for mains voltage, so you really need to replace it before attempting to use the enlarger. The transformer is contained within a separate box and is not part of the head assembly.