This may be a naive question, but I've got an older 1960s Fender amp I havent played in a while. When i switched it on it hummed pretty badly, worse than I ever recall it doing. I ensured all leads connect firmly, and the amp had been stored well (cover on at all times). Thoughts? Its kinda like an amp hum that needs to be grounded, but this is a two pin power lead with no ground wire ... so ... What can I do to get rid of the hum please?
Sounds like caps might need replacing. While you are in there change to a 3 prong grounded cord. This requires moderate skill with a soldering iron and knowledge of the circuit. If you don't have it, find somebody who does.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Guthrie on tone: https://www.youtube.com/watch?v=zmohdG9lLqY