On 4/11/2013 3:15 PM, Tom Fine wrote:
> The same expertise required to enable long distance lines of decent
> audio quality was involved with driving a light valve for optical
> recording and a recording stylus for electrical disk recording. Not to
> mention dynamic microphones, loudspeakers and impedence-matching and
> isolation transformers.
And the first practical condenser mic, invented by Western Electric's E.
C. Wente (who also held the patent on the dynamic mic).
Bell/Western Electric also held patents on the vacuum tube amplifier
(not the tube itself, but its use as an amplifier), the transistor, an
early limiter circuit, L-C-R mic placement for stereo recording, and, as
noted by others, the 45/45 stereo groove, independently developed by
Alan Blumlein. Nyquist, who was one of several people who developed the
sampling theorem that's the basis of PCM recording, was a Bell Labs
engineer. Johnson, who invented Johnson noise, was too. And the list