alright, so i have this problem with my tubes in my marshall overheating after playing for periods of 20 minutes. They will get really hot and almost appear to be on fire, at the same time the sound will completly drown out, or decrease in volume. my next question is what should my head and cab be set at ohm wise and stero/mono wise, assuming that i have a marshall 1960 cab and a marshall jcm 2000. like right now i have one cable going from the heads 16 ohm jack into the cabs mono/16 ohm jack, and the head is selected to 8 ohms.. my final question is, am i supposed to run two cables from head to cab and if so what is the settings on head and cab supposed to be... thanks guys for the help!