After more and more file testing, it does seem to be file specific throughout. Even down to one or two tracks out of an entire album. My backups come up with good copies of at least all tracks on one bad album (John Moriarity) from a 4/21/14 backup.
What is puzzling is that I have never played any of the DSD files on anything but MC, and usually a full album at a time.
I examined the binaries of a good and bad file. On a bad file:
00-0x50b misc ascii text (probably a mix of binary as in a header) text includes DSD, data, fmt, .h with blocks of zeros in between.
0x50c-0x3d89c all 0x4b's (K)
0x3d89d-0xd6260 assorted 8 bit chars
0xd6261-0x968005b all 0's (to end of file)
On the good file same song:
00-0x50b misc ascii text (same as above)
0x50c-974555 assorted 8 bit chars
0x974556 start of tag data, first variable TIME, end tag data 0x974575b
0x974575c-0x974605b zeros to end.
Difference between endpoints of the two files is 0xc6000, seems to be on an even boundary of something. I'm not familiar with the internal format of DSD files, so maybe this info will be significant to another.
I have never had disk corruption, bad sectors, any kind of errors on the disk containing these files, yet there are several of bad ones scattered about. This seems to have occurred somewhere between 4/1 and mid-May. And all files follow the same pattern, and maintain their approximate length, which to my mind leaves out the possibility of disk or controller errors.
Is it possible that some interim bug occurred in one of the updated MC's that might have caused this? I update all MC copies regularly and automatically. It would almost seem like a library background run of some sort, but those should all be read only except for tag fields.
Also, so far, every file that has had this problem has been a native DSD download from BlueCoastRecords. I haven't yet found a track damaged that didn't originate there, but upon download they all played fine.
I put up the original good version for download if anyone wants to examine it:
"HERE" Perhaps there's something about the layout that may cause problems under certain circumstances.
Thanks for any assist in tracking this down.
--Bill