I have experience with computers and electronics. I have been an auto tech and was previously a computer programmer/builder. I am interested in buying old broken and non working audio equipment on ebay and repairing/restoring them for my own enjoyment. I have a good knowledge of electronics but not as much on older equipment with tubes and more analog circuitry. Are there any books or online resources to get into restoration of these old receivers, amps, tuners, etc. (I am talking 70's and early 80's Marantz, Sansui, and brands like that from that time period. Also maybe a list of testing equipment needed besides a multimeter. Any help would make my year! Thanks!