Hello, Jay,

Please look at my Web site  -- that
should answer many of your questions. Please click on the graphics for larger

Tapes are commonly divided into one, two, and four tracks on quarter-inch. These
are imaginary divisions that only exist in the magnetic patterns, there is no
physical manifestation.

The track width is basically the same for two-track stereo and two-track mono.
Half-track mono is the same as two-track mono as far as I can tell. Both use
0.082 inch track widths.

Quarter-track tapes have four tracks with (starting from the top) 1 & 3 being
left and right.

When you flip the tape over, what was 4 and 2 now show up in the same spot as 1
& 3 providing a second program on the tape. "Flipping" involves which edge is
uppermost. The oxide side of the tape always faces the head, so "sides" are a
holdover from discs and manifest themselves in which-edge-is-on-top.

Four-channel, quarter track records four channels in one direction for
quadraphonic reproduction. This was an attempt in the 1970s to bring surround
sound to the home with speakers in each corner of the room.

There are many variations in this, and understanding them all is a lot of fun
(at least for me). I've cataloged many additional options on the Tips page--and
I'm still finding details about more.

There are several unrelated axes in determining what is on the tape:

Mode (analog, digital)
Track configuration
Noise processing

I think that about covers it. Do the multiplication of the different options and
you'll see there are literally hundreds of combinations--a handfull more likely
than most.

I am making a business out of being able to play almost every format on 1/4-inch
and 1/2-inch tape up to four channels.

Oh yes, three channels (mostly on 1/2-inch tape) were used in the 50s and 60s as
a mastering format.  Many of the Frank Sinatra albums were recorded that way,
for example.

In the very late 1970s and through the 1980s, track densities kept increasing.
The record, I think, for analog audio is the Tascam 238 Syncaset that puts 8
tracks on a standard 1/7-inch wide cassette.

While good conservative practice was no more than 12 tracks per inch--many
thought 8-tracks per-inch should be the limit, we see up to 16 tracks on

Fostex and others might sold 8-track 1/4-inch reel machines and 16-track
1/2-inch reel machines.

I don't play those, but people who can are linked on my resources page.

"8-track" cartridges were different in that the head stepped up and down. There
were four positions for stereo programs (four separate programs separated by
height) and two positions for quad programs.



Richard L. Hess

Quoting Jay Gaidmore <[log in to unmask]>:

> 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.
> If a reel to reel player is described as 1/4" broadcast 2-track, what
> does 2-track mean, as well as 1-track, 3 track, and 4-track?  In a
> 4-channel, 1/4" machine, to what does the 4-channel refer?  How about 2
> and 3 channel?
> I have seen many reference to setting the correct azimuth.  What is this
> and how do you set it correctly?
> As you can see I am very much a novice trying to learn.  References to
> website or publications that would help answer the questions above would
> be greatly appreciated.
> Thanks in advance,
> Jay
> Jay Gaidmore
> Archivist
> The Library of Virginia