THIS UNIT WORKS GOOD AND IT IS LOUD ON A 6X9 50 WATT SPEAKER. I BELIEVE THIS UNIT IS MONAURAL EVEN THOUGH IT SAYS A AND B AND YOU CAN CUT ONE OFF, AND THAT SIDE IS DEAD AT THAT POINT AND OF COURSE THE OTHER SIDE IS WORKING AND YOU CAN DO THE REVERSE AND YOU CAN COMBINE A AND B AND HAVE THEM BOTH WORKING, DAVID BOGEN MUST HAVE THOUGHT OF THIS DOING IT AT THE INPUT BECAUSE THIS UNIT ONLY HAS ONE AUDIO OUTPUT TRANSFORMER. THE CHASSIS BEAUTIFUL ON THIS AMP, BECAUSE IT IS COPPER COATED I BELIEVE IN ALL THE LABELING IS BY THE TUBE SOCKETS. THIS IS A COLLECTOR'S ITEM, AND IT DOES WORK, BUT UNDERSTAND THIS, IT HAS SEVERAL PAPER CAPS IN IT AND IF I WAS GOING TO KEEP IT I WOULD REPLACE ALL OF THOSE. THE LARGE FILTER CAPS LOOK LIKE THEY WERE CHANGED ALREADY. SO THERE YOU HAVE IT FOLKS ALL MATCHING SCREWS AND DAVID BOGAN NAME APPEARS ON THE UNDERNEATH SIDE OF THE TOP CASE COVER IN LARGE PRINT MADE IN THE 1950S I DO BELIEVE. Shelf -7