Quote Originally Posted by Skorzen View Post
Thanks for the information, it looks like that discussion will be very helpful. As both of these heads use an 82 VAC lamp, is it a safe (or at least good) assumption that the 45S head is the same as the 23 head electronically?
Earlier versions of the 45 head, to my understanding and from research done on the web, were similar, and the DDS head, again, to my understanding, had the same problem with the now obsolete optoisolator. The Dual Dichro (not"S", for internally stabilized) wasn't so afflicted. This was the model with the seperate stabilized voltage supply. I came across a guy who was supposed to be able to fix the various incarnations of the 45 & 23 heads (including the much more complex later ones) but by the time I found him, I'd solved my problem by picking up a used DD head on that bay thing.

BTW, the older head was two and a half stops faster than the DDS; same voltage and lamp wattage, different lamp.