I just rebuilt the power amp stage of one of these on Friday and the correct schematic of the amp is the Laney KB80 .It uses 2N3773 as Output devices and Tip 31 /32 as drivers . Laney took over H/H .The power amp modules of the H/H MXA 100 ,MXA150 plus the Laney KB80 .The main difference is the output devices 2N3055 FOR the !00 and 2N3773 for the 150. The other difference is the Secondary voltages of the mains transfomer . Be sure to check the longtail pair TR3 and4.