 It was identical to the Blue Stripe, apart from having its overall gain reduced, except for the wiring of the outer two Class A power amp tubes which were switched to Pentode operation instead of Triode for a 10w RMS increase over previous Simul-Class amplifiers (15w/75w) making 25w/85w.Mesa ultimately ended the Mark III's production since it overlapped with production of its successor, the Mark IV, which was introduced in 1990.Mark IIIs were still in steady production around 1994, and finally ceased as late as 1997, 11 years after their launch.