"David Looser" wrote in message
...
"Brian Gaff" wrote in message
...
Its quite funny as most of the cassette machines on sale now in the dying
era of tape use DC or permanent magnets for erase/bias.
Funny old world.


I'd be interested in knowing where your statistic that "most" of the
cassette machines on sale now use DC bias comes from. Personally I doubt
it. You may well find that although DC *erase* is common enough in cheaper
cassette recorders, bias is AC. It takes a lot less power from the
oscillator to provide bias than to erase a tape.

David.

Agreed. I remember looking at an old Magnetofon 76cms deck with
AEG spools, just post WW2. The bias/erase oscillator was a separate
unit, an add-on with its own psu.

Iain