Re: [ARSCLIST] Information on open reel players and tapes

[Michael Shoshani <mshoshani@xxxxxxxxxxxxx>]

Jay Gaidmore <JGaidmore@xxxxxxxxxxxxx> wrote:

>Could somebody lead me in the right direction to finding out more about
>reel to reel players and tapes?  I am looking for information that will
>help me understand the differences between 1/4 track, 1/2 track, and
>full track, full-track mono, 2-track mono and stereo, 2 track-mono, full
>track head and two track head.  
>

The basic "reel to reel" tape that first comes to most people's minds
is a tape that is 1/4" wide.  Originally the entire width of the tape
was used for recording purposes, obviously in mono.  This is known as
full-track mono (or simply full track), and was a professional
standard.  The tape was recorded only in one direction; if you turn it
over and play it, all you get is backward gibberish.

For home consumer use, where the average layman was not so concerned
about fidelity of sound as he was with how much he could cram on the
tape for which he paid good money, this 1/4" tape was literally split
in half: the recording head only recorded on the top half of the width
of the tape.  Turning the tape over then permitted the "other side" to
be recorded, using the opposite track.  This is known as a 2-track or
half-track mono recording: the tape has two "sides" but is in mono.

In the professional field, the idea of using two tracks, each half the
width of the tape, provided a single-direction way of recording in
stereo.  This was known as two-track or half-track stereo, and like
full-track mono is only recorded and played in one direction.  This
configuration was not limited to "pure stereo" recordings; it was
common practice at EMI in the late 50s and early 60s, to record takes
with all the instruments on one track and vocals on the other track,
for convenience in making a mono mixdown.

The consumer market got its version of stereo tape by splitting the
1/4" width into four tracks, two of which were played at the same
time.  In this instance, what would appear as the first and third
tracks were recorded in one direction, then the tape would be turned
over so that the second and fourth (now upside down and in "first and
third" position...this is starting to sound like a football game)
tracks could be recorded.  Originally two separate heads were used for
this; as the technology to record the tracks with only one head was
developed, the old "staggered-head" system was phased out, leaving the
"inline" system most of us know today.  This, by the way, is
four-track (or four-channel) stereo.

>I have seen many reference to setting the correct azimuth.  What is this
>and how do you set it correctly?

In order to get good fidelity in recording and reproduction, it is
necessary to have the recording/playback heads properly aligned in
relation to the tape, not only so that the head is parallel to the
direction of travel but also so that the recording/playback area of
the head is in correct vertical alignment, not too high or low. Most
machines have at least one small Phillips screw by which the angle of
the head can be adjusted, because as with all things involving moving
objects, it can get misaligned.

Hope this helps,

Michael Shoshani
Chicago IL