I own both, have worked on both. Only real differences I see in new vs old is that in the old gear, you get a sense, just looking at it, well, some of it, not all of it, that someone poured their heart and soul into building the best product possible at the time. You really don't get that impression from the new stuff, it's all manufactured, cookie cutter, and not designed or built to last forever.
That being said, I do know the new stuff is far more capable power-wise than the old, better parts (mosfets back in the 80's were 10 amps each max, today they make them in the same physical size but all the way up to 290 amps each), bigger parts, and Class D has helped make that possible. As for the sound quality of old vs new? I think it really has a lot more to do with average modern class D sound vs old Class AB sound, I can tell the difference there, but the difference between an old Class AB and a new Class AB? They sound the same to me. Though I am admittedly not one with a good ear for SQ. I believe it has far more to do with the drivers being used rather than the amplifier, when going for best possible SQ.
Love it or hate it, old school stuff is gone. It's still out there, but it's all used, and old, and got leaky caps and things.... Kinda like buying an old car. Yeah, it's fun, it looks different, it goes different (more torque than most new average run of the mill daily cars?) but in the end it has the same function, just a different "feel and look".
That being said, I do know the new stuff is far more capable power-wise than the old, better parts (mosfets back in the 80's were 10 amps each max, today they make them in the same physical size but all the way up to 290 amps each), bigger parts, and Class D has helped make that possible. As for the sound quality of old vs new? I think it really has a lot more to do with average modern class D sound vs old Class AB sound, I can tell the difference there, but the difference between an old Class AB and a new Class AB? They sound the same to me. Though I am admittedly not one with a good ear for SQ. I believe it has far more to do with the drivers being used rather than the amplifier, when going for best possible SQ.
Love it or hate it, old school stuff is gone. It's still out there, but it's all used, and old, and got leaky caps and things.... Kinda like buying an old car. Yeah, it's fun, it looks different, it goes different (more torque than most new average run of the mill daily cars?) but in the end it has the same function, just a different "feel and look".