More demagnetizing issues arise. Today’s inquiry, from inSync reader Bart G, is about digital recorders: “I own 3 Panasonic DAT recorders. Nowhere have I ever read anything about demagnetizing them. Should I do this and if so, what is the best method?”
You don’t need to worry about this on your DAT machines. DAT (R-DAT), ADAT, DA88, VCR, and presumably all rotary head type recording devices do not suffer the magnetic build up normally associated with linear analog recording machines. The rotating head assemblies are made mostly of aluminum and the actual “head” is a tiny sliver (less than 1/8 inch) ceramic and metallic material mounted in the edge of the rotating drum. There is really not much to retain magnetism. In the digital world it doesn’t matter as much anyway because digital information is, by definition, more absolute than analog. It takes quite a lot of magnetism to change a one to a zero on tape (which is very different than loosing a couple of dB at 12k). Besides, with modern error correction schemes the chances of even a few misplaced bits affecting the signal are remote.