Hi, picked up an unknown Quad amp today and i am unable to identify the unit, boards in side are X07-1700-10 which is an amp board 60 watts but cant find any more details on the rest of the boards. X11-1090-00 and x15-1080-00. Has 2 channel, all mix , R mix, SQ and discreet. apart from its maybe 1972 to 1974 cant find any more info