I'm far from being versed w Johnson's but,. If this is the beast pictured below, It appears from some quik misc. impromptu blog searches, this pic and color codes on the unit itself, it should be both....AC in and regulated DC out.
http://www.ebay.com/itm/173640-Volta...p2054897.l5659
Do you have a copy(or a link) of the print you're looking at you could post?
Edit...hold the phone!! I see what you're after and why, I found the the print of your system I think, cool. i'll post it if I can and explain.
tblsur,
Check your PM's. Doesn't look as if the image went so I'll try to post the accompanying image here(or below, lol) as well.