I figured this would be a good enough place to post about this. So, I have been getting into vintage audio gear as a hobby. I would like to progress into being able to diagnose and repair problems that some of this old gear will undoubtedly have. I know the absolute basics of electricity. Does anyone have any suggestions as far as you tube videos, or books? I'm mostly talking about solid state stuff from the 70s into the 80s. Anyone else doing this as a hobby?