I had a bit of GAS and just picked one of these amps up this past weekend. It appears to be an early 70's model but I honestly don't know much about them. It sounds pretty nice through my Genz Benz neo 1-12 though. So will it do 4 ohms with adding another 8 ohm cab to the extension cab output? Yes, this part confuses me. It still has the 2-prong plug on it, which I need to replace as well. Any good resources on these amps? Also, it has Sylvania EL34 tubes in it. Were these stock tubes with these? Thanks in advance.