"Dave Plowman (News)" wrote in
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In article ,
Brian Gaff wrote:

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.

Do they really? The results would be appalling. And given
most things these days are a handful of chips I can't see
why - the cost of providing AC bias would be tiny.

I did a little study of available ICs for building cassette recorders. I
found no chips that included an on-chip bias oscillator. I found application
notes for building mono tape recorders with no bias oscillator, but all of
the ANs for stereo recorders showed an external bias oscillator.

The whole business of portable recorders seems to have gone almost
completely digital. Note that my Sansa Clip Plus includes a mono recorder
with a surprisingly effective microphone, along with the complete high
quality digital music player and FM tuner.