Are 8-track & 4-track cassettes compatible? Can the same calibration tape be used?

Описание: I had a question recently from a viewer about whether he could purchase a calibration tape and expect it to work his 8 track cassette recorder. I just got a 488 that has been sitting in my projects pile for ages working , so I thought i'd take the opportunity to investigate exactly how Tascam's and Phillips' formats for 4 track and 8 track heads differ - Phillips in this case refers to the common, garden-variety commercial cassette format used in the sony walkman, car stereos, home stereos, etc.

tried playing back several tapes in my Tascam 488;- a 4 track recording made on a 244; a commercial tape my mum must have bought from woolworths or Tower records or some other long-defunct record store several decades ago, and a Teac MTT-122BN 1kHz level test tape .

To better visualise the way the 488's head was responding to the different cassettes, I colour coded a diagram from the 488's service manual using adobe Photoshop i.

I go into more detail in the video but here is a brief summary of my conclusions;-

The tracks on a 4 track head are narrower than those on a a phillips head, but they do line up, so you can playback a prerecorded tape intended for home entertainment on any four track, its just that side B will play backwards.

Tracks , 2, 3, and 4 recorded on a 4 track tascam unit will be played back clearly on tracks 1, 2, 7 and 8 respectively of an 8 track tascam. Some of the same information may also appear on other tape tracks due to partial overlap of regions.

The Teac test tape I have appears to be printed with a special head that puts signal accross the entire width of the tape, meaning it cna be used to set playback levels of any format of cassette recorder. But if you have a calibration tape recorded using a phillips or tascam 4 track head, you will not get reliable results when calibrating track 3 through 6 of a tascam 8 track cassette recorder.

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