A Brief History of the Marque
Allgemeine Motorfahrzeug AG in Berlin
This was another of the short-lived factories which assembled motorcycles in Germany during 1924 and 1925. Production was limited to lightweights powered by 149cc Bekamo two-stroke engines.
They were associated with Robert Schmidt.
Another source says "The Allgemeine Motorfahrzeug AG in Berlin was a marketing company that offered light motorcycles with 150 cc two-stroke engines under the brand name AMAG. The engines were probably from the adjacent engine [builder] Schmidt". Karl Reese provides a reference to this in his in his book Motorräder aus Berlin: "The Schmidt company delivered the four-stroke engines and AMAG motorcycles were apparently built for contractors. AMAG itself contributed only sales."
Sources: Tragatch p73, GTU Oldtimerservice, et al.