The answer to your question is very simple. For the most part, they don't exist. To have them means that the recording studios have to convert to machines capable of making these recordings. If you ask the same question about DVD-A recordings you get the same answer. Why invest in a machine that may be obsolete if the format dies. So even though many studios can make a high resolution digital recording, they are not in native SACD format and have to be digitally converted.
Why reissues? Most of the recordings in the studio vaults are on analog tape. There are millions (well, at least a whole lot) of hours of tape that can be remastered and reissued in a higher resolution format. These are recordings of proven sellers versus the crap shoot of recordings of new music. Which would you do?
Why reissues? Most of the recordings in the studio vaults are on analog tape. There are millions (well, at least a whole lot) of hours of tape that can be remastered and reissued in a higher resolution format. These are recordings of proven sellers versus the crap shoot of recordings of new music. Which would you do?