martedì 7 maggio 2013

stereophonic audio 1954

Stereophonic Audio:
Its Commercial Beginning

Photo of Cook Binaural Disc and Adapter The 1954 Cook Binaural LP Disc and Binaural Phonograph Adapter
This adapter, shown mounted on a monaural Livingston phonograph arm,
allowed two monaural cartridges to play the twin record tracks.
Precise placement of the two needles at the beginning of the tracks
was always a problem.

Photo of Magnecord binaural tape recorder

The 1951 Magnecord Binaural tape transport and amplifier
This Model PT6-BA2HZ used the standard PT-6 transport
modified with two staggered, half-track record/playback heads.

Photo of Magnecord amplifier

Photo of Magnecord amplifier

Interior view of the Magnecord binaural amplifier, Model PT6-BN

The First Four Years of
Stereophonic (a.k.a. Binaural) Products
The following products were offered to pioneers of stereophonic sound and high-fidelity audio
before the advent of the single-groove stereophonic disc and FM-multiplex stereo broadcasting.
Some stations combined their AM and FM transmitters to broadcast the left and right channels
of experimental binaural broadcasts, and a few tuners with separate AM and FM
tuning controls and circuits were made to receive those broadcasts.

Note that "binaural" in the 1951-54 era meant ordinary stereophonic audio, whereas
today "binaural audio" refers to a richer three-dimensional audio experience by
the use of headphones for listening and head-mounted microphones for recording.

1951   $884 Magnecord PT6-BN "Binaural"2-channel magnetic tape recorder & amplifier
1953     $35 Livingston "Binaural" phonograph arm for Cook twin-track binaural records
1953 $1195 Ampex 403-2 2-channel stereophonic tape recorder
1953    $345 Bozak B-204 twin 2-way, single cabinet speaker system for stereo sound
1953    $150 Livingston "Binaural" amplifier, 10W/channel
1953      $50 Permoflux B-DHS-28B or B-DHS-17B Binaural Headset
1953      $70 Cook BN/mn "Binaural" preamplifier, 4 tubes
1954        $6 Cook binaural clip-on conversion unit for monophonic phonograph arm
1954    $100 Audiosphere "Bi-Fi" tape playback transport for binaural recordings
1954    $145 Bell "3-D Binaural" amplifier/preamplifier, 10W/channel, 11 tubes
1954    $190 Brainard A-200 binaural amplifier/preamplifier, 18W/channel, 11 tubes
1954    $120 Brainard T-200 AM-FM binaural tuner
1954             Browning RJ-48 AM-FM binaural tuner
1954    $170 National "Horizon Criterion" AM-FM binaural tuner