multitrack compact cassette

4-track and 8-track aka 'Portastudio' multitrack audio cassette tape
4 different rectangular audio cassettes

4 examples of 90 minute compact cassette - TDK and That's

introduction to multitrack compact cassette transfer

Multitrack compact cassette machines became hugely popular in home studios during the 1980s and ‘90s. Whereas stereo compact cassette recording uses 2 tracks (left and right) for side A of a tape, and 2 tracks (left and right), in the other direction for side B, a 4-track head assembly allowed musicians to record separately to all four tracks in the same direction, with the added possibilities of over-dubbing. 8-track doubled that capacity.

At Greatbear, we carefully restore and digitise all variations of 4-track and 8-track compact cassette tape.

We offer a range of delivery formats for our audio transfers. Following International Association of Sound and Audiovisual Archives TC-04 guidelines, we deliver 24-bit / 96 kHz high resolution Broadcast WAV files, together with MP3 audio file or audio CD listening versions. We're happy to create any other digital audio files, according to your needs. We can also digitise to 24-bit / 192 kHz, if required.

We can provide the appropriately-sized USB delivery media for your files, or use media supplied by you, or deliver your files online. Files delivered on hard drive can be for any operating system - MacOS, Windows or GNU/Linux and filesystems (HFS+, NTFS or EXT3).

Multitrack compact cassette tapes vary widely in duration and in the extent of physical tape degradation, so we always assess tapes before confirming the price of a transfer.

We offer free assessments please contact us to discuss your project.

For an introduction to our assessment and treatment processes, please see our guide to "what happens to your audio tape".

4-track compact cassette machines

Many happy hours have been spent using 4-track cassette machines such as the Tascam 244 Portastudio to record music over the years. These machines were robust but are now close to 40 years old. Cassette tape can still sound good after a long time if stored correctly and transferred with serviced and calibrated tape machines.

We use the Tascam 234 rack version of their multitrack for transfers with dbx noise reduction if necessary. This is a robust machine, built for studio use and therefore easier to maintain than the smaller multitrack cassette machines with their built-in mixers.

8-track compact cassette machines

The Tascam 238 was a multitrack machine that managed to squeeze 8 tracks from the 3.81mm (0.15 inch) compact cassette tape width. Quality was pretty good due to the fast recording speed of 3.75 inches per second (ips) or 9.5 cm/s which is twice the normal cassette deck speed. The 238 had dbx and the 238S had Dolby S noise reduction that helped to improve the signal to noise ratio. We have both machines at the Greatbear studio.

In addition to the mechanical problems of wear that affect the tape transport, the direct drive capstan motor circuit board can start to fail, causing the tape speed to increase wildly. While these can sometimes be repaired by replacing the capacitors, it can be neccessary to replace the whole board and motor, which we have recently done - getting hold of (apparently) the very last one available from Teac UK!

multitrack compact cassette format variation

track formattape speed inches per second (ips)noise reductionsupported
41 78Dolby B
41 78Dolby C
43 ¾Dolby B
43 ¾Dolby C
41 78dbx Type II
43 ¾dbx Type II
83 ¾dbx Type II
83 ¾Dolby S

For the replay and digitising of multitrack cassettes we use Tascam Porta 1, 134, 234, 238 and 238S to support all speeds, track formats and noise reductions types:

  • 4-track cassette at standard speed using Dolby B, C or dbx noise reduction.
  • 4-track cassette at double speed using Dolby B, C or dbx noise reduction.
  • 8-track cassette at double speed using dbx or Dolby S noise reduction.
view from tape end of cassette, showing very dark brown 3.81mm / 0.15" magnetic tape

Compact cassette close-up: tape width 3.81mm / 0.15"

enlarged image shows stack of 4 rack-based Audio Cassette Decks with multiple buttons and level indicators

Tascam 234, Tascam 134, Tascam 238 & Tascam 238S machines

4 plastic rectangular tape cassettes with rulers indicating dimensions 10 cm × 6.3 cm

Cassette tape dimensions: 4 x 2.5 x 0.5 inches (10 cm × 6.3 cm × 1.3 cm)

multitrack compact cassette tape risks & vulnerabilities

Compact cassettes sometimes have physical problems that need to be addressed and repaired before a good transfer can be made. These can be:

  • respooling loose or damaged tape in the existing cassette shell
  • splicing or refixing the leader tape to a reel hub
  • reshelling the tape in a new cassette shell
  • baking sticky tape
  • addressing fungal growth on tapes stored in less than ideal environments

Due to the small tape width and slow speed that normal speed cassettes run at, they usually have a reputation for poor sound quality and reduced frequency response. This is often the case - but with the right tools well-recorded cassettes can sound very good and the best can be got from other recordings.

It’s quite common for the Azimuth in cassette recordings to vary between tapes and recording machines. Unless you are playing back a tape recorded from a known, properly-calibrated tape machine, it is often necessary to adjust the playhead azimuth to get the best high frequency response when digitising audio cassettes. On many cheaper tape players this is difficult, not very accurate and is often not done, so tape transfers can suffer. The machines we use all have easily-adjusted playhead azimuth to get the best from your tapes.

Multitrack audio cassettes can also have other specific problems not seen with standard stereo audio cassettes:

  • Dolby B, C, S and dbx noise reduction were all options with these formats and ascertaining which was used, if not originally documented, can be tricky. Dolby S cards in Tascam 238 machines can also be problematic and require time consuming component replacement.
  • Low speed (standard cassette speed) and Hi speed (double standard cassette speed) were both options but not always available on all machines so to offer a complete service a wide range of replay machines is needed.
  • While some multitrack cassette recorders were well-engineered, they were all made for the home and project studio market so can be difficult to repair, with some of their original parts having been cheap and/or unreliable. The direct drive capstan on Tascam 238 decks is notorious for component failure and new motors are not available.

multitrack compact cassette recording history

The TEAC Portastudio 144 was the world’s first 4-track recorder based on a standard compact audio cassette tape. It hit the markets in 1979, followed by the Portastudio One in 1984.

For many amateur musicians the 4-track recorder was a liberatory tool.  It enabled them to cheaply record several instrumental and vocal parts on different tracks in the comfort of their own home, rather than use an expensive recording studio. Many recordings we have access to today would have never been possible without the 4-track recorder – they were an essential part of the do-it-yourself recording revolution in the late '70s and early '80s.

Portastudios were also used by mainstream artists to record demos (the whole of Bruce Springstreen’s sixth album Nebraska was recorded on a four track tape recorder).

On 4-track recorders you could record more than four tracks via ‘track bouncing’. Bouncing was a multitrack phenomenon whereby you can combine any two or more recorded tracks onto an unused track, thereby freeing up the original tracks for re-recording. So on a 4-track, you might bounce, say, three tracks to one, leaving you three potentially open tracks, or three tracks to two (a stereo pair), leaving you two available tracks to record to.

4-track recorders were followed later by models which could record up to 8 tracks of music. Multitrack recorders are still popular today, but record to hard disc or SD-card, rather than analogue tape.