I just picked up a Rollei EC 6x7 (color head) enlarger which is the same enlarger as the Nikor being discussed. My question is do I need a transformer/power supply, which is common for color head enlargers?

It has a regular 3-prong plug, i.e., not a special plug to a transformer. On the back it says "Input 120 VAC, 50-60 Hz, Output 82 VDC 85 watts" (for the Omega Cat. No. 471-400 Quartz Haolgen lamp). Does this mean the voltage is reduced and converted to DC by the enlarger as-is? Looking inside the head, I would have to take a good part of it apart to see if there is a diode circuit that does this (there's not much room for a transformer and the head doesn't feel heavy enought to contain one).