I had the Minolta 45A head and really disliked using this item. The head I owned was practically brand new as the previous owner also thought very little of the unit and did not use it very much. I thought it was a real bargain when I purchased the head but quickly changed my mind. Aside from the long printing times at the higher enlargments the stupid thing would shutdown if it thought the unit was being overheated.
Fine for small enlargments but push the head up the column and watch what can happen. Also the bloody "light tubes" are expensive and get progressively weaker with use. This requires the head to leave the light on for a longer time and increases the rate of wear on the tubes. A cycle that ends up with a spent tube and more cash flow from the user.
I even had "Colorbat" send me the whole Printing with a Minolta 45A package. Worked with this head for 3 months and then sold it.
I am really glad that it is gone. On a scale of 1-10 I give this head a -2. As a side bar... I own and shoot Minolta 35mm cameras (for 25 years) and really like the equipment. Minolta makes some very good equipment in my mind but this head is definitely not one of these.