cassette

Apr

2021

Philips VCR – the first home video cassette recorder

For thegreatbear.co.uk, I get to photograph and document racks and racks of beautiful 'obsolete' tape machines in the Greatbear studio. From time to time pictures of our machines pop up elsewhere online (I'm convinced our machines are the best-looking on the internet), and this month one of our Philips N1500 VCRs is featured in Australian electronics magazine Silicon Chip (May 2021).

The siliconchip.com.au article describes Philips' development of VCR: the first cassette-based video tape recording system designed for domestic use, following the success of their revolutionary Compact Cassette audio tapes, recorders and players (1962 onwards). This is set in the context of U-matic, the Panasonic Video Cartridge, Betamax and VHS.

The article is part 3 of a well-researched and illustrated feature series on The History of Video Tape. Scroll down for a text extract from the article - we recommend subscribing to the whole series.

"Philips [had] entered the domestic open-reel market with half-inch VTRs beginning with their 1969 release of the desktop LDL-1000. Although easy to use, it lacked a tuner, forcing users to have existing TV receivers modified to supply video and audio signals for the VTR. Such modified sets were known as receiver monitors.

The LDL-1000 achieved some success, but recalling the success of their audio Compact Cassette system (siliconchip.com.au July 2018), Philips began development of a cassette system for video recording.

Their N1500, released in 1972 (just one year after Sony’s U-matic), offered an integrated design. Containing a tuner and a timer and able to supply a standard television signal output, the N1500 hit the spot with consumers, except for the problem of tape length. The N1500 can claim to be the world’s first domestic VCR (video cassette recorder).

Philips’ VCR system mechanism, like their compact cassette mechanism, was offered royalty-free to manufacturers who agreed to maintain the design standard and use the VCR logo. You can see a video of a VCR tape loading at https://youtu.be/9-Bw8m65mVY

The VCR cassette stacked the supply and [take-up]reels above each other in a coaxial design. At only 125 x 145 x 40mm, it was much more compact than the standard U-matic cassette.

Its width (under 60% that of U-matic) helped moderate the size of the entire tape drive mechanism. While this elegant solution offered a genuinely compact medium, the complexity of its threading mechanism meant that its reliability was only fair.

Using a half-inch tape with a conventional 180° degree omega wrap, the Philips VCR was able to offer 60-minute record/play times at the CCIR/PAL speed of 14.29cm/s (5.63ips).

Philips attempted to market to the United States in mid-1977, but NTSC’s higher field rate (60Hz vs CCIR/PAL’s 50Hz) forced an increase in tape speed to around 17.2cm/s (6.8ips), giving only 50 minutes for a cassette. A thinner tape, offering the full 60 minutes for NTSC, proved unreliable in use.

Other compromises finally made their VCR unsuitable for the American and other NTSC markets, while the introduction of VHS in 1977 convinced Philips to abandon the US market. As a result, their VCR was only marketed to the UK, Europe, Australia and South Africa.

Philips tape loading is simpler than that of the U-matic. Sony had put every interaction (transport, heads and guides) in the external tape path. Philips cleverly used two cassette doors: an upwards-hinging one at the front for tape extraction, and a sliding one at the right, allowing the audio/control track head and the pinch roller to intrude into the cassette.

Video entry and exit guides, and the capstan, also intruded vertically into the cassette as it was loaded downwards, giving much a more compact tape transport than that of U-matic. The pinch roller and audio/control heads, mounted on a pivoted arm, were swung into place for playback and recording.

Where the U-matic head drum was designed with slip-ring contacts from the heads to the VCR electronics, Philips used a rotary transformer design that had already been used in Ampex 1-inch open-reel VTRs. Although more difficult to design and manufacture, the rotary transformer overcame noise and signal loss caused by slip-ring corrosion or misalignment. It would become the design of choice in Beta, VHS and following formats.

The N1500 was developed as far as the N1520 production model. Dispensing with the inbuilt tuner, the N1520 offered record/playback and full electronic assembly/insert video and audio editing. Released in 1973, it beat Sony’s VO-2850 workalike U-matic editor to market by a full year.

Regrettably, the Philips VCR format suffered from unreliable tape loading/handling, and that dreaded one-hour time limit.

Philips did develop a long-play VCR, the N1700 series, by halving the tape speed. Not released until 1977, when the Sony-JVC/Beta-VHS melee was well underway, the Philips VCR lapsed into obscurity. "

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Extract from The History of Videotape – part 3 Cassette Systems by Ian Batty, Andre Switzer & Rod Humphris, Silicon Chip, May 2021

Aug

2013

The Magnetist – Audio Cassettes in Contemporary Culture

As lovers of magnetic tape and obsolete media, we keep our eyes open for people who remain attached to the formats most have forgot.

A recent film posted on Vimeo features the creative life of part time chef, noise musician and tape DJ Micke, also known as ‘The Magnetist’.

The film follows the Stockholm-based artist through his life as a ‘tapeologist.’ From demagnetising tape in order to create soundscapes, to running a club night comprised of tapes scavenged from wherever he can find them, Micke demonstrates how the audio cassette remains a source of inspiration within counter culture.

The Magnetist from Filibuster on Vimeo.

The wider resurgence of cassettes is evident from the forthcoming Cassette Store Day, an event that will be marked in record stores in the UK, USA, Europe and South America.

New tape labels are popping up all the time. Tapes are now often preferred to CD-Rs for short run albums in do it yourself punk culture, as releases blur the line between art object and collector item.

So what’s behind the sub-cultural obsession with the audio cassette tape? Perhaps it is no more complex than novelty value and nostalgia. It may however be evidence of the persistence of analogue technologies in an era where digital technologies appear to have colonised our relationship to sound and vision.

Is there a yearning to resist the ways digital media shapes how we listen to music, both at the level of sound quality, and the promiscuous skipping through mp3 files?

You simply can’t do that with tape. You have to rewind, fast forward or listen the whole way through. Its a mechanical process, often shrouded in hiss.

What is certain, fashion or no fashion, the wheels on the Great Bear tape machines will keep turning.

Jun

2013

Digitising Audio Tape – Process, Time & Cost

Last week we wrote about the person time involved in transferring magnetic tape to digital files, and we want to tell you more about the processes involved in digitisation work.

While in theory the work of migrating media from one format to another can be simple, even the humble domestic cassette can take a substantial amount of time to transfer effectively.

Doing transfers quickly would potentially keep the costs of our work down, but there are substantial risks involved in mass migrations of tape-based material.

Problems with digital transfers can occur at two points: the quality of the playback machine and the quality of the tape.

Let’s focus on the playback machine.

Each time a cassette is transferred we have to ensure that the cassette deck is calibrated to the technical specification appropriate to that machine. Calibration is a testing procedure where a standard test tape is used to set the levels for tape to be digitised. The calibration process allows us to check tapes are played back at the correct speed and audio levels, that wow and flutter levels are set and the azimuth is aligned.

Azimuth refers to the angle between the tape head(s) and tape. Differences in Azimuth alignment arise from the azimuth of the original recording. You cannot know this information from just looking at a tape and you will get a sub-optimal transfer unless you adjust your machine’s azimuth to match the original recording.

Regularly checking the Wow and Flutter on the tape machine is also very important for doing quality transfers. Wow and flutter refer to fluctuations in speed on the playback mechanism, flutter being a higher rate version of wow. If you have listened to a tape you will probably be familiar with the sound of warped and woozy tape – this is the presence of wow. All tape machines have wow and flutter, but as components in the mechanisms stretch there is the potential for wow and flutter to increase. It is therefore essential to know what level the wow and flutter are set on your tape deck –less than 0.08% Weighted Peak on our Nakamichi 680 machines – to ensure optimal transfer quality.

Not all cassette machines were made equal either, and the quality of playback is absolutely dependent on the type of machine you have. There is a massive difference between the cheap domestic cassette machines made by Amstrad, to the cassette decks we use at Great Bear. Nakamichi machines were designed to squeeze the most out of the cassette, and their performance is way above the standard ‘two head’ cheap domestic machines.

Even with a Nakamichi deck, however, they have to be regularly checked because they are fragile electromagnetic machines that will drift out of specification over time. When machines drift they slip out of alignment, therefore effecting their operating capacity. This can occur through subtle knocks, everyday wear and tear and general ageing of mechanical and electrical components. For example, with extended use the grease in the components dries up and goes hard, and therefore affects the movement of the mechanisms.

Problems can also arise with the tapes themselves.

Most issues arise from tapes not being played back in well calibrated machines.

With audio cassettes the potential for azimuth error is increased because the speed the tape moves pasts the head is very slow. The tape therefore needs to be assessed to see if it is in a playable condition. It is played back in mono because it is easier to hear if there are problems with the azimuth, and then the azimuth is manually adjusted on the machine.

Migrating tape is unquestionably a ‘real time’ process. You need to listen and monitor what’s on the tape and the digitised version to ensure that problems with the transfer are detected as it is happening. It is a very hands on activity, that cannot be done without time, care and attention.

May

2013

Audio cassette transfer and Martin Parr’s The Non Conformists

We were recently sent a collection of recorded interviews with residents of Hebden Bridge, a mill town in the Pennines. They were recorded on regular, domestic tapes of the mid-1970s, the kind that were sold in shops such as Woolworths or WHSmith.

As magnetic cassette tapes go, these cheaper tapes can often deteriorate at a fast rate because they were aimed at a mass consumer market, and therefore not made with longevity in mind. These tapes however were in excellent condition, and no issues arose in the digitisation process.

Here is what Susie Parr told us about the project behind the tapes, and the publishing plans for the material later this year. We were very happy to be part of a creative project that will enable the stories to be shown to new audiences because of digitisation.

‘In 1975 photographer Martin Parr moved to Hebden Bridge, a mill town in the Pennines, with some friends from art school in Manchester. In a project that was to last five years, he started photographing the area, documenting a traditional culture and way of life that were slowly declining. Susie Mitchell, who also lived in Hebden Bridge, wrote about the people and places that Martin photographed. Together they built up a record of the day to day lives of mill-workers, game-keepers, coal miners, hill-farmers and chapel-goers. As part of their research, Susie and Martin would tape record their conversations with some of the characters they met. Thirty years later, the elderly audio tapes have been digitised and the photographs and texts are going to be published by Aperture in a book called The Non Conformists. In September, an exhibition will open in London.’

Below is an audio snippet of one of the tapes. This is a raw unprocessed version, notice the tape hiss inherent in these types of recordings. Sympathetic noise reduction to reduce this type of noise, can be process on these file if necessary.

parr-cassette-oral-history-snippet-1975

Dec

2011

8 track cassette capstan motor Tascam 238 Syncaset

We specialise in tape transfers, many of which are multitrack cassette tapes.

Tascam, Fostex and Yamaha sold cassette multitrack recorders in the golden days of home recording in the 1980s and ’90s. The 4 track format was especially popular but an 8 track format was also developed that squeezed even more out of the small tape width of the cassette.

We love these cassette formats and their accessibility helped start many musicians’ careers. Unfortunately one of the best 8 track machines, the Tascam 238 Syncaset also suffers from a common and frustrating problem that renders most of these machines useless over time, the dreaded direct drive capstan motor failure…

The 238 and other 8 track and high quality stereo tape decks, the 688 and 122 MkII and III, used a direct drive capstan motor for precise speed control and reduced speed variation or wow and flutter (w/f). The circuit that controls this motor fails in certain ways causing lack of speed control and in our case the capstan motor wizzing away at a crazy speed, not the 9.5 cm/sec that it should do.

This here is the culprit – you can see the attempted repairs which didn’t ultimately work.

One common failure is that the surface mount electrolytic capacitors fail or their capacitance changes to such an extent to cause speed problems. These can be changed for standard through hole caps but you do need to be very careful as the tracks are damaged very easily – good tools are essential.

The other point of failure in the circuit is the BA6304F SO16 IC – we even changed this but the motor still didn’t turn!

There was some suggestion from previous repairers that the grease at the end of the capstan flywheel hardens over time. increasing the friction and causing problems with the circuit.

This can become frustrating quickly, especially when you have a large archive of cassettes to digitise.

When we can’t repair we reluctantly do the next best thing and buy the whole replacement part but this is another exercise in frustration. Teac parts and Teac UK don’t have any european supply of this capstan motor (part no. 53700075-01) anymore as of November 2011. Interestingly about 6 months ago they did at around £60 GBP, then about 3 months ago they had one left at £160 GBP!

Lots of emails later to Teac US, Teac Canada and Teac Japan there seem to be a nice stock still on shelves somewhere and at reasonable prices UNTIL you ask them to ship to the UK when you discover they can’t do this and I’d need to go through Teac UK!!! I’m pretty persistent but I gave up finally even though some of the support staff tried to be pretty helpful.

We find support for older machines from the original manufacturers is not good generally and unreasonably expensive when you can find it. This is similar across audio and video, semi-pro and professional products. Some companies are easier to deal with and have a better parts situation than others, but stockpiling machines, parts, manuals and obsolete knowledge is the best course of action.

What we finally did that worked and was a good solution was purchase 3 Tascam 122 Mk III stereo cassette decks which use the same but a later revision of the capstan motor, (part no. 53700121-00). One machine was donated for the cause and the capstan motor removed, modified and refitted in the 238. The 122 motor has a few factory extras, such as these resistors, shown here:

You also need to solder / desolder the speed pads, to change the motor speed from 4.8 cm/s to 9.6 cm/s that the 238 needs to run at.

It’s also a good idea once you’ve got the capstan motor apart to clean the old grease from the seat, check the end float which can be adjusted using the screw shown on the left and apply new grease to the capstan end.

Put it all back together – be careful to solder the wires to the motor to the correct pads – they’re different on the 122 and test… Ours worked almost perfectly.

As the transport hadn’t been used for a while the reel motor would intermittently stop as if sensing the tape end. This can sometimes be loose counter belts but on the 238 it’s a digitial counter. We cleaned up the leaf switches on the transport top and also sprayed a small amount of deoxit into the inside of the reel motor. A bit more use and it finally worked to spec…

For 4 track and 8 track multitrack cassette transfer, see our dedicated page, and please contact us for more information.

Oct

2011

azimuth adjustment when you transfer and convert cassettes to cd

Cassette tapes run at a very slow speed of 1⁷⁄₈ inches per second (ips) with a very small track width of 1.59mm

Cassette decks when they left the factory or a service centre should have been aligned to a standard reference for the position of the record and play heads. Unfortunately they often weren’t all the same and over time the alignment can drift, get knocked out or manually ‘fiddled with’ by an owner.

What this means is that unless you’re playing back your tape on the machine it was originally recorded on, you may not be getting the maximum quality as the angle of the head to the recording or azimuth will not be optimal.

Without calibration tones recorded at the start of the tape (which is very unlikely on most domestic cassette tape recordings), you must set the playback azimuth manually. A few high end tape decks, namely those made by Nakamichi, either had a easily accessed Azimuth Adjust or could even automatically adjust this throughout the tape. The Nakamichi Dragon was one such tape deck and could be the best, if working well, for high quality playback.

If you want to transfer or convert a cassette to CD and adjust the azimuth yourself this is the easy way to do it:

Look at the tape path (everything the tape will move across) and if it looks brown and dirty get some isopropyl alcohol and give it a good clean with a cotton bud.
If you haven’t demagnetised your deck for a while now would be a good time to do it..
Power up your cassette deck, which hopefully works correctly and doesn’t have too much speed instability!
Pop your tape in the cassette well and start to play.
Turn your amplifier’s volume up and if you can put it in Mono.
Now, look under the tape machine’s playback or combined record and playback heads you should see a small screw or nut possibly with anti tamper paint on it.
Using an appropriate tool, turn this nut or screw a little left or right while listening to the audio.
You should hear the recording, especially if it has a lot of high frequency content such as cymbals etc. get bright and dull sounding or more technically get more in or out of phase.
Your aim is to get the most in phase or bright sounding playback.
Sounds better now?? Great, start to record using you favourite computer audio software. We like SoX for the control but there’s a huge range out there.

Nov

2009

Information Terminals M-300, cassette tape transport alignment gauge

The regular service of analogue machines which will involve the mechanical alignment then electrical alignment / calibration is really important if you’re attempting to get optimum transfers and reduce any risk of damaging the potentially fragile tape.

While some of our machines are serviced by others we like to regularly check them and have gradually brought our regular servicing in house. Of course this needs specialised tools, test tapes and gauges, often totally unavailable new now.

On a lucky eBay day I happened to win one of these beauties, an Information Terminals M-300 gauge. This enables you to accurately set the tape guide height and also the head stroke. It is a universal gauge and can be used across many decks.

Nakamichi tape deck owners have had a hard time doing this part of their servicing as the original Nakamichi gauges are very very rare now as is this.

A member of the naktalk mailing list though recently borrowed our gauge and has had it measured and will soon have a small batch CNC machined and made available. These remanufactured gauges will have a few small modifications to improve the design.

Thanks to Willy at www.willyhermansnervices.com many more tape deck transports will be able to be aligned correctly.

Apr

2009

Microcassette Transfer to CD helps Crown Court case

We’ve recently been involved, with Mobray Woodwards Solicitors, in the audio transfer of important evidence in a local Crown Court case.

Even given the poor quality or the recordings, made on the slowest tape speed of 1.2 cm/s we were able to make transfers to CD which were clear and understandable with CD track markings for easy access to specific sections of the audio.

Microcassettes, until recently, were used regularly for voice recording in small, portable dictaphone type of machines. Their fidelity is not high but when used for voice it is usually acceptable.

Greatbear are able to transfer all formats and speed of microcassette in addition to 1/2 speed standard cassettes that were common for voice recording of interviews and meetings in the police service, inquests, etc.

For more information on high quality audio tape transfer and restoration please visit our transfer pages.

cassette

Philips VCR – the first home video cassette recorder

The Magnetist – Audio Cassettes in Contemporary Culture

Digitising Audio Tape – Process, Time & Cost

Audio cassette transfer and Martin Parr’s The Non Conformists

8 track cassette capstan motor Tascam 238 Syncaset

azimuth adjustment when you transfer and convert cassettes to cd

Information Terminals M-300, cassette tape transport alignment gauge

Microcassette Transfer to CD helps Crown Court case

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