I have six of these, and thought it would be best to cover them in a single large article, so here goes.
First of all, though, a word about bias and erase, which are key factors in the evolution (or otherwise) of these machines. If you were to record a straight audio signal onto magnetic tape, it will come out distorted. That’s the laws of physics for you. The first method of getting around this was to offset the signal with a DC voltage. Not a perfect solution, because it generated additional noise and limited the maximum level of audio you could put on the tape, but a start. This is DC bias. Later it was discovered that mixing the audio with an AC voltage at a frequency far higher then the tape can handle gave vastly superior results. The high frequency died off as soon as the tape left the record head, leaving just a clean audio signal behind, and so AC bias was born.
Also, a DC-energised erase head (or a permanent magnet) will magnetise the particles on the tape uniformly in the same direction, with a rather noisy result. An AC voltage at a frequency far higher than the tape can handle (indeed, the same as the bias frequency, only at a much higher level) randomises and neutralises the magnetic orientation, leaving just the familiar ‘tape hiss’.
So AC is better than DC in both cases. AC techniques were well established when the Compact Cassette was developed in the early 1960s; DC, on the other hand, requires less electronics which allowed recorders to be manufactured at lower cost. You can probably guess the rest…
Stellaphone ST 473 (1967)
I was given this by a friend many years ago. It has never seen use by myself, having tested it only once – mechanically OK but a loud squeal from the loudspeaker. Whether this was merely a problem with switch contacts or a more serious component failure I have never looked into, essentially because it has no mains power facility and takes five(!) ‘C’ cells – a tangible reminder of the days when ‘C’ cells were sold loose – and is therefore rather awkward to use today.
This is the earliest type of cassette mechanism, as introduced by Philips. It was designed to be as simple to operate as possible and comprises a single large rectangular control – push towards the cassette for record or play, or left for rewind or right for fast forward – and an interlocking Record button. This can be pressed down only if (a) the main control is in the ‘Stop’ position and (b) if the write-protect lever at the rear of the cassette compartment is actuated. Pushing the main control forward locks it down; pull back to stop the tape and it pops up again. There are also volume and tone knobs (with very serrated edges!) and the then-obligatory record level/ battery condition meter. And that’s it – no locking fast wind, no pause control, no counter, no auto-stop, no built-in microphone and no eject facility – the tape is lifted out by gripping its left- and right-hand edges.
There are three sockets, all of the DIN type. The first is a two-pin one and has a loudspeaker symbol adjacent – pretty self-explanatory. The others are a five-pin 180 degrees and a six-pin 270 degrees (with centre pin), labelled ‘1’ and ‘2’ respectively. The first of these is wired conventionally except for the input being at microphone level and so requiring a special lead for recording from a radio or amplifier – this was apparantly standard Philips practice at the time (q.v.). The second appears to be for an external power supply and/or remote switching, amongst other things.
One of those items which I’ll probably never restore to working condition (although it seems generally in good nick), but it’s nevertheless good to have an example of the original Philips mechanism in the collection.
Hitachi TRQ-291 (1972)
My late father purchased one of these back in the day. I can remember him telling me subsequently that it was a rather more expensive model than what he had budgeted for at the time; presumably, having been a reel-to-reel user since the 1950s he was looking for comparable performance. Anyway, by the late 1980s it had become forgotten amongst a plethora of stereo machines owned by both my parents and myself. Then, sometime around 2010, I saw one at the National Vintage Communications Fair. The chap wanted just a couple of quid for it so I snapped it up. Unbelievably, just a short time after this my parents were having an attic clearout and turned up at my front door: “look what we’ve found”!
The unit seen here is, therefore, a ‘cut & shut’ hybrid utilising the best components of the two. The exception is the record/play head – both were badly worn, so I fitted a generic mono head (the type which Maplin used to sell) which I just happened to have lying around. My parents’ machine still had its original PVC carrying case (which can be seen in the ‘group shot’). As a result, its aluminium top had fewer scratches but the NVCF one had less of the print worn off. I opted for the latter.
The early 1970s was definitely a stylistic high point in consumer audio, and this was clearly a high-end model of the time. It’s by far the heaviest unit of the six and offers the best performance. Recordings made on it display a noticeably boosted treble, which I’m fairly certain is due to the replacement head, but this merely adds to the ‘quality’ feel.
Compared to the Stellaphone recorder it’s very much ‘early modern’, lacking only a built-in microphone which became universal on all later models. It’s the earliest example I have seen of the subsequently-ubiquitous ‘figure of eight’ mains connector and it also runs from a nice round number of four ‘C’ cells, as do all the following machines. Recording level is manual using the tiny meter on the top plate. In practice it’s necessary to have this punching well into the red in order to get a good signal onto the tape, and since there’s no pause control it’s not possible to set the level before recording (unless a test recording is made and the tape then rewound). Cassettes are placed directly into the compartment and the lid then closed; afterwards the ‘Eject’ key flips the lid open and almost somersaults the cassette in a rather messy fashion!
Auto-stop, actuated by tape tension, was probably established by this time and a ‘feature’ of this model is based around a pair of contacts at the rear of the tension sensing ‘peg’ which when closed produce a similar kind of loud squeal as heard on the Stellaphone recorder, only this time intentional (technobabble: it’s a positive feedback loop). In this way a short squeak emanates from the loudspeaker when the tape ends and the recorder shuts off. It seems rather pointless, since the mechanical ‘clunk’ is perfectly audible, but I would guess that it has its uses when playing through remote speakers, e.g. a background music system. It can be turned on or off by a switch next to the counter.
Socketry is comprehensive, and this unit has no fewer than three audio inputs – in addition to the usual microphone input and DIN in/out it also has a 3.5mm jack labelled ‘Radio’, which as far as I can tell is the same as ‘Aux’. Unlike later machines, plugging in a DIN connector disconnects the internal speaker, in the same manner as the ‘Extsp’ (extension speaker/earphone) jack.
And finally it should be mentioned that fast winding on this machine is fast! In fact, it’s the second fastest I’ve come across, beaten only by my Akai deck which has a separate motor for the spool drive. Why this is the case, when it has a similar motor and mechanical arrangement to the others, I have no idea.
Pye EK 3227 (1978)
This was a skip rescue in the early 1990s. Flash photography makes it look shabbier than it really is, in fact, it’s not in too bad condition considering where it came from.
Cassette recorders had become standardised by the late 1970s. Mains/battery operation, built-in microphone, automatic recording level and ‘lid loading’ were common to all. The more expensive models like this one offered a pause key, a tape counter and a tone control as well. Case construction had also changed, utilising a more resilient, impact-resistant plastic, and the protective PVC carrying cases were no longer supplied.
This model is unusual in that it lacks a DIN socket. However, when you consider that the DIN output (to connect to an external amplifier) on most of these machines is nothing more than the speaker output via a resistor, then the ‘Aux’ and ‘Ear’ jacks do exactly the same job. What it actually lacks is an external speaker output – the resistor has to be bypassed in order to enable this.
Its only flaw is the second or two of distortion at the start of music or speech during a recording, while the automatic recording level turns itself down. Otherwise, it’s a good machine with pretty decent recording quality.
Suga KC-920 (c1980)
‘Tat’ begins here. This must have been the first model to feature an all-plastic transport mechanism. Surprisingly, it’s little different to the others in terms of weight.
I bought this one new, the cheapest on the market, from my local Tesco store – the original Tesco Value cassette recorder! From memory, it was a penny change from sixteen quid – the next cheapest was a Waltham model which was a whole pound dearer. Perhaps I should have bought that one – it lacked a pause key and a tape counter but was probably mechanically superior, although the electronics may have been no better. But I was sold on the features and anyway, to a schoolboy armed with a cash gift and saved pocket money, that extra pound was quite a leap.
So as things turned out, this was my introduction to the rough and ready world of DC bias and DC erase. Recording quality is little better than AM radio and is accompanied by lots of noise – particularly noticeable when played back on a higher quality machine. Otherwise, it’s quite conventional except that that it apparently has just one head – the two heads are combined in the one block, something I’ve never come across before or since. (Really? Have another look at your National Panasonic RQ-443SD (q.v.) – Ed.) It has the usual sockets; in this case the DIN in/out is on the right-hand side.
Like the Stellaphone, it’s now a non-worker and will most likely stay that way.
Ferguson 3T07 (c1980)
This one came from one of those Cash Convertors/Cash Generator stores – it’s a good job that these places don’t sell much pre-1985 stuff, otherwise I would likely end up spending a fortune and become buried in it!
It looked interesting… Fully featured with a tone control, pause key and counter, a good quality, well-built mech with a satisfyingly positive key action and even a slightly larger speaker than all of those described above, it appeared to be quite a high-spec model and would certainly have been way out of my reach back in the day. But the electronics are rudimentary, based around a single integrated circuit. Bias and erase are DC, so recording quality is poor. Quite why the designers skimped in this area, I really don’t know. Perhaps, in that immediate pre-Walkman era, they thought that these machines would primarily be used for playback and so there was no point in spending money on the circuitry required to make a good recording.
Once again the usual sockets are provided – the mains input is on the right-hand side this time. Unfortunately, the right-hand hinge on the cassette lid is broken with the result that it doesn’t open and close easily – it requires a bit of wiggling. So it’s a bit of a disappointment, as well as something which I have absolutlely no need for, but I was curious – and you know what they say about curiosity!
Dixons SR7 (1986)
A late-era model which was found in a clearance bin in one of the eponymous stores and cost a fiver. It worked fine on batteries, the only fault found was a failed mains transformer. Fortunately, these transformers were a readily available component back then, so it was quickly fixed.
The transport mechanism is of metal construction but is lighter and lacks the ‘solid’ feel of earlier designs. All the usual features and sockets are present, and ‘cue & review’ and ‘one-touch recording’ have been added to the mix. I have always thought that the first of these is nothing more than a means of wearing out the heads quicker. Keys labelled ‘Record/Save’ and ‘Play/Load’ indicate that this type of recorder had found a new use by this time.
Unlike earlier designs which used a square-section drive belt, this one has a ‘flat’ belt, which if nothing else has a longer lifespan. The speaker is of a similar size to that in the Ferguson but has a larger magnet and as a result this unit attains the top score for playback sound quality. On the downside, it has a very lightweight capstan flywheel and music has always sounded a little ‘unsteady’ to my ears. But that won’t be important with data, though. Electronics look similar to the Ferguson, so recording quality is nothing special, but once again it’s not going to matter with data.
. . .
By the 1980s the demand for mono machines like these had fallen right off, and the alternative use as data recorders for home computers was short-lived. Today they are pure technojunk – even those who enjoy the ‘retro’ appeal of cassettes these days are unlikely to be interested in mono reproduction. Will this collection of six ever be expanded? Well, I don’t have any use for them (in fact, I don’t use cassettes at all nowadays), but then I’ve always fancied one of those high-end ‘landscape format’ models from the 1970s, so who knows what the future may bring…
The Technojunk Files 