|Barry's 8 Track Repair
|Solve the mystery: A brief explanation and
demonstration of how the 8 track format works
|The 8 track tape format was pioneered by William Lear, the same dude who invented and
manufactured the Lear Jet. Hey, I also repair equipment used in Lear jets! Must be fate.
Contrary to popular belief, Mr. Lear did not actually "invent" the 8 track format, since it was a
slow evolution of many tape recording concepts gradually coming together. Multitrack
recording had already been in existence, with its roots going back to the mid-30's. Les Paul
was the first artist to popularize the concepts of overdubbing and multitrack recording,
which enabled him to listen to a previously recorded instrument while adding another.
Les Paul's first experiments involved OVERDUBBING, which was the simple process of
recording a guitar part, then playing it back with a second recording machine to pick it up.
While re-recording the first guitar part, he could then play another guitar part. The second
recording machine now had both guitar parts recorded on the tape. The process could be
repeated, adding drums, voices, etc. until an entire song was completed.
There was a major problem using this technique: NOISE. Every time another part was added,
it added more room noise, hum, tape hiss and other artifacts inherent in tape recording. By
the time 6 or 7 parts were recorded, the noise began to overshadow the music. Another
problem was that there was no control of the instrumental balance once a new part was
recorded. If a new part was too loud, it could not be independently turned down - thus, the
new part had to be recorded again and again, until the balance sounded correct.
Thus spawned another new invention: MULTITRACK recording. By designing a recording
and playback head with many separate tracks (instead of the typical 2-track stereo head),
each part could then be recorded on its own separate track, meaning up to 4 instruments (in
the case of a 4 track system) could be recorded without overdubbing. The fact that nothing
had to be re-recorded resulted in greatly reduced noise and tape hiss. And since each
instrument and vocal had its own separate track, it could be turned up or down AFTER all the
recording was finished. This saved much of the high cost of studio recording time, since
everything could be tweaked just right during the mixdown process for the final recording.
The Beatles' Sgt. Pepper album was recorded on a 4 track console, with the expertise of
George Martin making it sound like many more tracks - not very noisy at all. With rock bands
demanding better fidelity and more tracks (for instance, to give each drum, cymbal and vocal
harmony its own separate track for greater flexibility during mixdown for stereo), the
recording industry soon evolved into 16, 24, 36, 64 and even 128 tracks. The Queen song
"Bohemian Rhapsody" and 10CC's "I'm Not in Love" both contain more than 100 separate
vocal tracks, giving these songs that huge vocal sound. They "stacked the tracks", meaning
that they recorded the exact same part several times to make it sound bigger and fuller.
If you listen closely to most John Lennon or Petula Clark songs, you can actually hear the two
distinct vocal parts (double tracking). This was common practice in the 60's and 70's. These
days, they use digital delay and other techniques to simulate the huge vocal sounds.
|So what about the 8 track cartridge format ?
|Sadly, the 8 track cartridge format has very little to do with the high quality, super-flexible
recording techniques previously mentioned. In the case of the 8 track format, "8 track"
simply means "2 tracks (stereo) times 4 programs". Thus, while the tape itself indeed has 8
separate tracks of audio information, only 2 are used at any one time. When the first
program is finished, a track change mechanism physically moves the playback head down a
notch, so that it now picks up the information on Program 2.
Since the tape runs at the relatively slow speed of 3.75 inches per second (compared to 15
inches per second on a high quality reel-to-reel machine), the sound quality leaves a bit to
be desired. And since the playback head moves up and down while the tape travels
horizontally across it, machines frequently suffer from alignment issues. And finally, since
Track 1 (Program 1 Left Side) and Track 8 (Program 4 Right Side) are at the very edges of the
tape, these two tracks are usually a bit weaker in output than the others.
You can now see where the terms "track" and "program" can be a bit confusing. Basically,
when the machine clicks, it goes to a new PROGRAM containing 2 TRACKS (left and right).
In the animation shown below, I drew the playback head MUCH taller that it actually is. In
reality, the playback head is not quite twice as tall as the tape width. This puts the tape in
danger of slipping over the top or bottom of the head on Programs 1 and 4, especially on
tapes which have the narrow foam pressure pad instead of the wider brass-spring felt pads.
Watching the animation, you can see where alignment is very critical to avoid crosstalk
between tracks, and why it takes a skilled professional to properly align an 8 track player:
|To continue our discussion of William Lear and his pioneering efforts, his "invention" was simply the
process of piecing together existing technologies in a somewhat clever way. The technologies he
employed had already been in use for years in one way or another:
1. Continuous loop tape cartridges (used for background music such as Muzak)
2. A movable record/playback head (every tape recorder already had head adjustments)
3. Audio amplifiers and recording circuits
4. Tapes contained within cartridges (used in radio broadcasting)
5. More than one audio track on a tape (it was called "Stereo")
|Since the track change operation moves the playback head in
an abrupt, jerky manner, the 8 track format has been called
"The only tape format that knocks itself out of alignment 4
times every album".
This is why it takes a skilled professional with many years of
dedicated experience with 8 track machines to properly align
your unit and make sure it STAYS in alignment FOR LIFE!
Only BARRY'S 8 TRACK REPAIR makes this promise.