Hi, i ve got prolem with my LM Rocker 500, the tube drive is not working respectively it works like reverse volume now. We change the tube but problem is still there. The tube is shining, but there is probably problem with anode voltage, so the tube do not amplify. The rest od the amp works OK but the drive-buton works as the overturned volume and turning it to right continuously quiets the amp. So probably there is a problem of power supply for the tube (no voltage on anode). Did you anyone have a wiring schematic of the amp? or just for this part? I think the LM Tube should be the same or simmilar.. so also diagram for MB LM tube will be helpfull. thanx a lot.