I have a 1961 Gibson GA-5 amp that is sick. When I turn it on it has an extremely loud buzzing hum and when I try to play through it, it sounds horribly out of tune, distorted, muddy, etc... I know it needs new wires, but could it also be the tubes. If so will I still be able to find tubes for this amp. If you need more info about the amp just let me know. Any help will be greatly appreciated.