I have been looking into this matter, and I am sure that HD PC drives are OK, but there are some (older ones) with which you can mess with some switches: DS0, DS1, DS2 and similar names. I don't know what they mean, but I feel if you can find a disk drive with such settings you can adjust it. You may want to take a look http://www.vienxu.com/korg0/
especially the file http://www.vienxu.com/korg0/files/teac7500_lo.jpg
which tells you about the settings for a TEAC disk drive for the T series.