It is not true that the upgrade has to be done via the HD: I did it both ways and it worked both ways. The reason was, that I didn't download the latest Ketron FT and the one I had failed. As I was impatient I copied everything with the same floppy (yeah, once you have a floppy which works with your PC AND the SD1 use this floppy for all files. If you're using 12 new floppies, the chance is higher, that one of the discs doesn't match your PC's or SD1's tolerance)
and it worked. Later I copied everything once again with the latest Ketron FT and it worked too. The only thing one really HAS to do is copying the first file (the OS) via floppy to the SD1 (at least I don't know of a procedure via HD). All sound files then can be transferred via cable to the HD.

Brgds Hansruedi