bg wrote:

Rumor has it that a record amp broke into oscillation thus adding
a bias to the audio.

That was what happened for the germans, they were initially using
Poulsen style DC bias.

I've heard that this "accident" was discovered by B&K.

Undefined abbreviation .... Valdemar Poulsen did invent the tape
recorder in principle, but as a wire recorder. There is only one country
of invention.

big snip ------------

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