I disagree (respectfully) with Fatparrot, in part, and I agree, again in part. I would say that the A70's and the Marantz qualify as vintage equipment and possibly the Missions as well. I think the SR2000 would drive the A70's quite effectively as they are an easy load. I still own a pair so I speak from experience. I also think they would do a good job with your musical preferences. As to whether they or the Missions could replace your Bose, I feel that is a matter of personal preference. I certainly feel the A70's are superior but it is really your opinion that matters.
Fatparrot is correct that your equipment may need some service. However this may not be all that expensive. I would recommend that you check out audiokarma.org where you can get advice and information from a group who specialize in vintage equipment. Lots of Boston and Marantz fans there and good, helpful people too.
I'll also agree that SACD is probably not the way to go unless you plan on going to a multichannel system in the future. As long as you stay with 2-channel systems you really won't be able to take advantage of the SACD format.
Anyway I hope you enjoy your equipment. I think you'll find it can give you a lot of musical satisfaction. Good luck.
Fatparrot is correct that your equipment may need some service. However this may not be all that expensive. I would recommend that you check out audiokarma.org where you can get advice and information from a group who specialize in vintage equipment. Lots of Boston and Marantz fans there and good, helpful people too.
I'll also agree that SACD is probably not the way to go unless you plan on going to a multichannel system in the future. As long as you stay with 2-channel systems you really won't be able to take advantage of the SACD format.
Anyway I hope you enjoy your equipment. I think you'll find it can give you a lot of musical satisfaction. Good luck.