These two amps sound great. I'm using a Dr. Z Mazerati (AC30 type head) with a '73 Marshall Super Lead through a Morley ABY box and into the same open back 212 with the speakers separated (Vintage 30's). One amp to each 8 ohm speaker. Each amp sounds great in the A OR B mode but when I combine the two (A AND B) the bass drops out and it sounds anemic and weak. Is this fixable? Did I do something wrong? BTW: I have both amps in the same electrical output but I put a gray ground lift on one of the amps so there's no ground loop noise. Any help would be appreciated.