A printing press is comprised of at least one dry offset printing unit. The window frame defines a window. Resultant underaged alloy then is cooled from the ageing temperature to a lower temperature and at a sufficiently rapid rate to substantially arrest the primary precipitation. The amplifier makes use of a control circuit to self-adjust quickly and respond to changes in input conditions, operating conditions of the optical amplifier and gain requirements while maintaining gain flatness and a low noise figure over a broad optical bandwidth and a wide range of gain levels.