Hi guys, so i just bought an 1972 ampeg V4 and it turns out its definitely got some issues. i had it shipped, whether these issues happened in transit or the previous owner was unaware, its got problems. obviously im not an amp tech, but i kinda wanna start learning about this stuff so i can hopefully in the future fix some of my own stuff, instead of paying and waiting for weeks for a tech to fix it. can anyone recommend some good books or some good sites that have information on understanding the inner working of an amp? thanks guys!