Audio cassette tape for synchronised 35mm slide projection
rectangular black plastic compact cassette labelled Scotch Ferric

Compact cassette for slide-tape presentation

introduction to slide-tape transfer

Prior to widespread digitisation, slide-tape was the popular multi-image, audiovisual presentation system used in educational and art contexts. The method typically used a 35mm photographic slide projector with synchronised accompanying audio tape. Recordings made on cassette tape for the slide-tape system were recorded across 3 channels: 2 for stereo audio and a third channel for the 25Hz pulse track, which cued the 35mm projector.

At Greatbear we have the specialist equipment to play back and extract the stereo audio from these tapes.

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).

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.

slide-tape machines

Our Tascam 133 multi-image recorder with Dolby NR, was developed by Tascam to lead the multi-image market.

slide-tape format variation

BASF cassette tape resting on plastic box with stack of 6 white plastic-framed colour transparency slides

35mm slides and compact cassette

dark brown cassette deck with orange knobs and amber lit VDU meter

Tascam 133 Multi Image Stereo plus cue track recorder

black plastic compact cassette with rulers indicating width by height 4 x 2.5 inches (10 cm × 6.3 cm)

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

slide-tape risks & vulnerabilities

Slide-tape cassettes share certain physical problems with all compact cassettes, which 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 cheap 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.

slide-tape history