There is one more thing about Meopta Meochrome.Because of dust it's better that enlarger is grounded.This color head is not grounded..Trafo is grounded but head not.Cable from color head have plug with 3 contact but cable is with 2 wire.Female connector on the trafo have only 2 "live" contact,the third contact for ground doesn't exist inside female connector.Nearest ground contact that you can make is under big screw on trafo and the other end of the wire under big screw on the top of color head.Just my 0.02$.