OK ... not expecting a diagnosis and maybe I’m just venting ... but I came home and turned on my amp and there is a steady hum coming out of my speakers! If the preamp isn’t on, it still hums, so it is a problem with the Carver. I moved the interconnects around, but the hum is still there. I know the amp is pretty old and of a somewhat unique design, but I am very disappointed that I can’t play any music on a Friday night. Does anyone have a wild guess as to what this can be, or what I can do further to diagnosis it? I have another higher power Carver amp I may switch out - a TFM-55. It’s a lot more power than I need for my speakers. I don’t know. Maybe I should sell the 55 and just buy a new amp. Any help or comments appreciated.