The "1959 Fender Bassman Tweed" is the most sought after amp in the world. The first Marshall amp was just a copy of the Bassman. The Bassman sales today for probably around 12 thousand or so. What makes this amp or any other vintage amp deferent than todays modern models? It has been said in books and articles on the net that the Bassman circuit is "legendary", and other such words, that shows us that this vintage amp as well as other amps of that era are different!
"Leo Fender" obviously set the standard for guitar amps. He also made many "guitars" that are "legendary" as well. I understand that the Seymour Duncan company studied the bridge pickups on vintage Telecasters to the point of even studying the effects of age on magnets (pickups are basically magnets with wire wrap around them). Did Leo know that he was doing things that would cause others to study his work well into the future? I don't think so.
So again what is the deference? Well of course first of all we have say that the "tube" is the one big difference. Most of us that have studied these things know that the way a tube distorts and the way a transistor distorts is deferent. But I don't think that is all. I believe It also has to do with being hand wired and the quality of the materials being used.
At some point manufacturing companies began to compete in a different way. When the transistor arrived on the scene there got to be a move toward miniterization and building electronic equipment for less and less overhead. Quality was less and less a concern. I'm not saying that companies didn't try to save money in the golden age of amps, but rather that I think there was less concern about that and more concern about quality. There were not a thousand deferent companies making components and other materials anyway. So the competition was in the area of quality. And how much would it cost to have rows of people soldering all day? How much would it cost to buy the same materials today?
Steve Day
Whenever you are looking at old Fender Amps one quick way that you can tell a good one from a not so good one is to look for "Fender Electric Instrument Company" on the front NOT "Fender Musical Instrument Company". That will mean that it was made before January 5th 1965 before CBS took over. That doesn't mean that there isn't some exceptions but it is a good rule of thumb.