hopefully this is the right forun, if it's not, im sorry. i have a peavey standard pa from the seventies (later seventies i think) and it has never failed me until now. recently when i turn it on, and hook it up to a cab, i can't get a signal to go through it, but it makes a loud humming noise. none of the knobs seem to affect this, and i don't know what to do. There is no problem with any of the cords, and the impedences match, so i'm wondering if the values of some capacitators may have drifted too far in the last thirty years. if anyone knows anything about this, or has a similar problem, please help.
thank you.