Project type: all audio

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 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

The DTRS (Digital Tape Recording System) aka DA-88 series of professional multitrack audio recorders were first introduced in 1993 by TASCAM / TEAC, followed in late 1994 by the Sony PCM-800 system. In 1995 the DA-88 won an EMMY award for technical achievement.

Both DTRS and Sony PCM-800 have similarities with their larger (VHS) format competitor (and predecessor) ADAT. DTRS and ADAT are both examples of Modular Digital Multitrack (MDM) technology.

The majority of DTRS tapes we digitise at Greatbear are master sound tracks for television post-production companies.

In 2012 the DTRS format was officially discontinued. It is still used in a few video post-production and remote recording environments, but music-only digital recording studios have moved on to hard drive recorders and Digital Audio Workstations (DAWs).

Developed in the late 1970s, PCM (pulse code modulation) digital audio harnessed the larger bandwidth of video tape technology to digitally encode an audio signal to magnetic tape. PCM digital audio was widely used for studio mastering until the introduction of Digital Audio Tape (DAT) in 1987.

At Greatbear, we carefully restore and migrate to digital files all variations of PCM audio recorded on Betamax, VHS, U-matic or other video tape. We are able to provide direct digital transfers, avoiding digital-to-analogue and analogue-to-digital conversion.

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).

PCM digital audio recordings vary 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.

Many valuable audio recordings were made on video tape either as a standard video soundtrack in mono or stereo or using the higher quality FM recording system. Having extensive racks of video machines allows us to save these recordings.

We use Audio + Design Sony PCM-701ES Professional machines for PAL / SECAM 625 recordings and the Nakamichi DMP-100 for NTSC 525 recordings, coupled with dual-standard replay Betamax, VHS and U-matic VTRs.

For PCM audio on Video8 tape we have a dedicated Sony EVS700UB Digital Audio Video machine.

direct digital transfers

In addition to supporting PAL / SECAM 625 and NTSC 525 recordings, we can also make direct digital transfers of recordings on all 3 systems, via the A+D Sony PCM-701ES Professional Adapter. This allows us to bypass the digital to analogue converter (DAC) in the 1980s Sony unit, so removing two unecessary stages of DA / AD conversion which is always preferable in recordings like these which are 'born digital'.

Given that PCM audio recordings all use video tape (in particular VHS and U-matic), they are prone to the same causes of degradation as video tape, including mould.

Often problems due to degradation can be more pronounced, as back-coated, high-quality tape was preferred and these tend to suffer from issues like Sticky Shed Syndrome more often. Certain brands / tape models such as Ampex 187 and 197 are particularly susceptible to binder hydrolysis and need 'baking' before it is safe to replay them.

Alesis Digital Audio Tape or ADAT is a magnetic tape format used for the simultaneous digital recording of eight digital audio tracks on to Super VHS (S-VHS) tape.

At Greatbear, we carefully restore and digitise 16-bit (Type I) and 20-bit (Type II) ADAT 8-track tapes, as well as sessions with higher track counts spanning multiple tapes.

As a born-digital format, ADAT recordings are best transferred at their native sample rate and bit depth.

We offer a range of delivery formats for our audio transfers. Following International Association of Sound and Audiovisual Archives TC-04 guidelines, we deliver 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 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).

ADAT recordings vary 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.

Like DTRS recorders, ADAT tape recorders use a video tape transport but running at a much faster speed (95.3 mm/sec which is circa 4 times the speed of VHS SP (PAL) format). Unfortunately most ADAT machines used a consumer tape transport that was not particularly rugged, often causing tape lacing problems which will damage tape. The later M20 machines used a much higher-quality transport.

The ADAT format was based on a VHS transport but even so, machine parts will not be available forever and key spares like the upper and lower head drum, while generally long-lasting will wear and replacements are very difficult to find.

Our ADAT machines include:

• Alesis ADAT XT
• Alesis ADAT M20
• Alesis ADAT LX20

While ADAT machines use standard S-VHS tapes, there are some issues which are specific to this multitrack digital format:

• The tapes run at around 4 times the standard VHS tape speed, so transports can wear out quickly.
• While expensive new, most ADAT machines used a transport common to domestic VHS machines, which do not respond well to heavy use.
• Direct digital transfer is preferable for making transfers, but this can be tricky without specialist hardware - especially when transferring multiple session tapes (16, 24, 32, 48 track sessions).
• While good quality VHS tapes could be used, S-VHS tapes were always recommended and the machines could be sensitive with some brands and exhibit high error rates.
• Some of the 'pro' branded ADAT recommended tapes like Panasonic RT-DA44 can actually degrade more over time than other SVHS tapes.

ADAT  / S-VHS specific tape brands / models

• Ampex 489
• HHB ADAT45
• JVC SE-180 SV
• Panasonic RT-DA44
• Quantegy DM 42

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".

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!

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

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.

Digital Audio Tape aka DAT or R-DAT, was used professionally by the audio and recording industry in the 1990s as part of an emerging all-digital production chain.

At Greatbear, we carefully restore and transfer to digital file all types of content recorded to DAT, and can support all sample rate and bit depth variations, including "long play" recordings made at 32 kHz.

As a born-digital format, DAT recordings are best transferred at their native sample rate and bit depth. Please refer to the table below.

We offer a range of delivery formats for our audio transfers. Following International Association of Sound and Audiovisual Archives TC-04 guidelines, we deliver 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 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).

DATs vary in duration and particularly 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".

We use Sony PCM 7030 / 7040, Fostex and Tascam DAT machines. The PCM 7030 has probably one of the best transports of any DAT machine built and is one of the more serviceable machines made. This is important as DAT as a format for recording is now obsolete yet there are many, many DAT tapes surviving and the machines, if not looked after, are breaking down!

DAT is an early digital tape format: essentially it is a digital video format adapted to record audio. Its longevity is similar to any video format because the rotary head system used to record and read the tape is subject to degradation and specialist tools are needed to fix the playback machines effectively.

The problem of acquiring the relevant spare parts to keep DAT machines working, like many of the machines we use, is also an issue because spares are no longer manufactured.

Almost all DAT machines could only record at 48, 44.1 or 32 kHz and at 16-bit resolution. A few later machines could record at 24-bit depth too, which we can support.

At 3.81mm wide and 0.013mm thick, Digital Audio Tape is fragile compared to other cassette-based digital and analogue formats. With well-preserved tape, and DAT transports that are correctly aligned and not worn, this format can still be reliably replayed, transferred and sound excellent.

The problems arise when the tape has become damaged or contaminated, for example with mould growth. Even a small crease or crinkle to the tape can cause significant problems often resulting in audio mutes where the machine's error-correction system cannot correct. Due to the slow linear tape speed of DAT, several seconds of unrecoverable errors can result from a small section of damaged tape.

Mould growth, even on a small scale, can be catastrophic, sticking one edge of the tape pack together so when wound or played the tape will rip and result in significant recording loss. See: Mouldy Tape

Based on a miniature video transport, DAT uses a helical scan recording system and therefore cannot be spliced for clean edits. Splices also risk irreparable damage to heads on the drum. A safer solution is to rehouse each spool in another shell.

There are reports of sticky shed syndrome (SSS) in some brands of DAT.

At Greatbear, we carefully restore and digitise all three types of small analogue cassette tape: the microcassette, Philips minicassette and Grundig Steno-Cassette.

Recognising that these formats and their players and recorders did not achieve very high quality, we offer two options and methods of transferring microcassettes, minicassettes and steno-cassettes

1. transfer using an original microcassette, minicassette or steno-cassette machine
2. transfer by respooling the tape into a larger compact cassette shell

We also transfer recordings from the older Grundig Stenorette 543 tapes. Respooling to an open reel is advisable.

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).

Given the variety of dictation cassette types / transfer options, and variance in the extent of physical tape degradation, 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".

There are three main types of small analogue recording tape: the Olympus Microcassette; Philips Mini-Cassette (aka minicassette) and the Grundig Steno-Cassette. These were commonly used for voice recordings and portable recording. Due to their inherent low recording quality they don’t have a wide frequency response, making them acceptable for voice recordings but rarely used for music (unless a lo-fi tape sound is specifically desired).

Microcassettes (5 x 3.5 cm) and minicassettes (5.5 x 3.5 cm) look similar but are not compatible, with minicassettes being slightly larger. Microcassettes are capstan-driven; minicassettes are not. This makes minicassette recordings more prone to wow and flutter, but also a more robust system allowing multiple stops, starts, rewinds, fast forwards. Grundig Steno-Cassettes are different again, and can be indentified by their larger size (6.5 x 4.3 cm) and integrated tape counter index.

Common brands of microcassette included Olympus, Sony, Panasonic, Sanyo and TDK. Sanyo also produced minicassettes for dictation and transcription markets, and Philips continue to do so.

Less frequently seen are the earlier Grundig Stenorette 1/4" tapes (top left in image above). It is advisable to wind the 1/4" tape to an open reel before transfer.

The microcassette format was developed by introduced in 1969 by Olympus. The tape width is the same as compact cassette, but its shell is much smaller. By using thinner tape and slower recording speeds, recording time was comparable to compact cassette with the MC90 tape offering 45 minutes per side at 2.4 cm/s or 90 minutes per side at 1.2 cm/s. Due to the small tape size, flexible speeds and portable recorders, the microcassette format was popular as a recording medium for dictation and in answering machines.

The Philips minicassette (1967) has a very slightly bigger format cassette shell. It has been used mostly in professional dictation machines, as its capstan-free design makes the transport simple, robust and suitable for repeated and quick forward and reverse winding. Playback speed is easy to alter for transcribing purposes but speed stability and wow and flutter are poor, making it suitable only for voice recording.

Developed by Philips in the early 1960s, by the 1980s this easy-to-use, highly portable format had become hugely popular for recording a vast range of audio projects. At Greatbear, we carefully restore and digitise all variations of compact cassette audio 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).

Compact cassette recordings vary both 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".

While audio compact cassettes were an extremely common format for many years both domestically and professionally, not all cassette decks were made equal. We have collected and restored a range of machines that can give the highest quality replay and offer the most flexibility for problem tapes. Issues such as tape handling, speed stability, low wow and flutter and ease of azimuth adjustment are important factors in choosing appropriate replay machines.

To help with this we use Tascam 122 MkIII, Nakamichi RX505 and 680 and 600 series 3 head cassette decks when we digitise stereo audio cassettes and Teac C-3x and Tascam 234 and 238 decks for high speed 2 channel, 4 and 8 channel transfers. These machines all have their transports regularly cleaned and demagnetised and are serviced and checked using test equipment such as the Nakamichi T100 Audio Analyser and Lindos LA101 / 102 test equipment.

For very large scale jobs, we can parallel ingest in batches of 8 or 16 using our racks of Tascam decks.

Sometimes, compact cassettes 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

In 1962 Lou Ottens' team at Philips invented a revolutionary medium for audio storage. It was introduced in Europe in August 1963 and in the United States in November 1964, with the trademark name Compact Cassette.

Compact cassette tape is 3.81 mm (0.150 in) wide, with each stereo track 0.6 mm wide and an unrecorded guard band between each track. At standard speed, the tape moves at 4.76 cm per second (1⅞ inches per second) from left to right.

In the early years, sound quality was mediocre, but it improved dramatically by the early 1970s when it caught up with the quality of 8-track tape and kept improving. The compact cassette went on to become a popular (and re-recordable) alternative to the 12-inch vinyl LP during the late 1970s.

For a time in the 1970s and 1980s the cassette was a ubiquitous part of everyday life. The invention of the Walkman in 1979 revolutionised how and where people listened to music. The compact cassette’s modest size allowed recorded music to be personal and portable. The cassette was used in many different contexts, from car stereos and police stations – making it one of the most flexible and widely used recorded formats in history.