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Toa MR-8T 8-track Cassette RecorderArticle from Sound On Sound, June 1988 |
If you thought eight tracks on standard cassette was an impossibility, think again. David Mellor assesses the world's first 8-track cassette recorder. Will it do to 8-track tape machines what the portastudio did to 4-tracks? Read on and find out...
The Toa name is, in this country at least, associated more with amplifiers and mixers than cassette recorders. I have used their amplifiers professionally and been quite satisfied with their performance and ability to withstand road abuse. But electronic circuitry is one thing, making an 8-track cassette recorder is something else entirely. I wouldn't take it for granted that a company capable of putting together a few circuit boards and a metal box could do the same for a piece of equipment which has to be built to almost infinitesimally small tolerances. Tascam or Fostex I could believe, but Toa?
My first impression of the Toa MR-8T was that it was a hell of a big box for a cassette machine. You could fit an army of Walkmen inside with room for their spare boots. 4U high, 19 inches wide and getting on for 15 inches deep, including connectors and switches. It looks pretty tough and chunky too, which is often a good sign of quality. Taking a close look at the cassette mechanism shows the record/playback head to be mounted on a cast alloy carrier rather than the bit of bent tin that you're lucky to get on a typical domestic stereo machine. The heads appear to be motor-driven to their working position rather than the solenoid action which is cheaper, but thumps the head block against the stops with a vigour that is almost bound to cause misalignment sooner or later. Needless to say, any misalignment in an 8-track cassette mechanism would have disastrous effects on performance. I don't think it should happen here.
An internal examination revealed nice, neat circuit boards and tidy wiring. It all goes towards creating an impression, and as far as observation can reveal, the MR-8T is a quality piece of equipment.
Having established that the Toa MR-8T is a serious contender for the home recording dollar, the next question is exactly how do they fit all those tracks in?
The answer is by using their head - or, in this case, two heads. Where you would normally expect to find a single record/playback head, there are two, configured as in Figure 1. Obviously, it was considered easier to separate the tracks across two heads rather than to build them into one stack. This raises an interesting point. If this had been a reel-to-reel machine, this type of construction would not be possible. Why? Because the tape could not be accurately edited. Many people edit multitrack tape - even with modern technology the good old razor blade still has its uses - but nobody, or nobody with a good understanding of what is possible and what is not, edits cassette tape. I suspect the Toa designers were scratching their heads for ages wondering how to get eight tracks into one head stack before someone thought of this clever solution.
The erase head is similarly divided into two sets of four. It's worth thinking about whether this split arrangement could cause any timing difficulties. After all, a spacing of half a centimetre will produce a time-difference of around 50 milliseconds, which could be important. I thought about it for a while and came to the conclusion that it would make no difference for tracks to be separated in time on the tape, as long as they are played back with the same separation. Still, it doesn't matter what anyone thinks about it, what difference does it make in practice? None. The system works OK.
Usually, the concept of a multitrack cassette machine revolves around the combination of recorder and mixer in one package. There are very few 4-track cassettes which are just that - the recorder with no mixing facilities. The Toa MR-8T is a sort of halfway house between these two. It couldn't be called a 'portastudio' (apologies for borrowing Tascam's phrase), because its facilities are too limited. But then again, it's more than just a multitrack recorder. Let me explain what it does...
On a conventional 8-track tape recorder you would expect to find eight inputs and eight outputs. You would not expect input level controls, headphone sockets, or any form of mixed output. You have to use it with a mixer. On the MR-8T, there are eight input level controls, one per track. There is also an eight channel monitor mixer, so you can use it without a mixer if you wish. The monitor mixer has gain and pan controls, and you can hear what's going on via the headphone socket, which has a level control, or via the monitor outputs at the back, which haven't. By any standards, it's rudimentary, but it's damn handy. I can see budget reel-to-reel machines sporting facilities like this before too long. It's a nice loud headphone socket, by the way.
The advantage of having these facilities is that the MR-8T can be used as a stand-alone unit, without a mixer. Or it can be used with a simple eight input, two output mixer - using the MR-8T's internal mixer for monitoring. Either way, it will cost you a lot less to get into 8-track recording. And using the second method will give very nearly all the facilities you could want to record an 8-track demo. OK, so a proper recording mixer will provide a few extra frills. It will probably add several hundred pounds to the total bill too.
How the MR-8T works is probably best explained by an example. Wiping the sweat of another sleepless night from my brow... (That's enough of that literary stuff!)... I opened the large box marked 'Toa MR-8T' and plugged its IEC cable into the mains. I plugged my headphones into the appropriate socket on the front, and my drum machine into input 1 at the back. I could hear the rhythm as it was recorded by turning up the monitor level on channel 1 and panning it dead centre. I set the level going onto tape with the record level control, in conjunction with the 12-segment LED bargraph meters. Fortunately, the recording level has no effect on the monitor level. Thus, I had the level that suited the tape, and the level that suited my monitoring requirements, simultaneously.
Once I had done that, I plugged my synth into channel 2 to record a bass line. I didn't have to do anything to set a monitoring level for my already recorded track 1, because the MR-8T switches from Line In to Tape automatically. I heard the drum machine replayed exactly as I heard it when it was going down. I set recording and monitor levels for the synth on track 2, then played the part onto tape.
A similar pattern was followed until all eight tracks were full. For mixdown, I connected the sockets labelled 'Monitor Out', on the back panel, to my stereo tape recorder. I adjusted levels until all sounded good, then committed my tune to stereo tape.
If that's not a painless procedure then I don't know what is. It was a bit bothersome reaching round the back to keep replugging, but if I was going to buy the machine then I would put it in a rack and wire it up to a patch bay so that there wouldn't be that problem.
I didn't get to use any outboard effects during my little session, which shows that the mixer section of the MR-8T does have its limitations. But I hope it's clear from my tale that it is possible to use the MR-8T without any additional studio equipment, apart from a pair of headphones. All that is needed is a couple of instruments, and a domestic cassette deck for mixdown.
It is possible to use an effect, even though there are no proper auxiliary sends. Each track has what Toa call an 'accessory' send and return. They mean insert points. You can take signal from any one channel, send it to an effects unit, then return it to the same channel to be mixed as normal. This is only possible on a channel by channel basis, and only when you replay a track - not record. If you wanted effects on several tracks, then you would need one effects unit for each track. I can't honestly see this feature getting a lot of use. If I had one reverb unit, then I would rather add a little effect to all the tracks, by putting the mixed stereo signal through it, than to add reverb to just one track in mono. Some reverb units (like the Alesis Microverb) can mix a stereo input signal with the reverb to give a stereo output, some can't (like the Yamaha SPX90). I would have been happier if Toa had made overall reverb possible with units like the SPX, rather than give 'accessory' sockets for each track. Some you win...
Before I go on, I should say that I'm not complaining about the lack of an auxiliary send. I think Toa have struck an agreeable balance in the facilities they have provided. Individual auxiliary sends would have added an extra 1U in rack height anyway.
It's no good having all the facilities in the world if the sonic performance isn't up to scratch. The possibilities for poor results are several. With a track width so narrow, I would expect noise and tape dropouts at the very least. Add to that an uneven frequency response caused by the tape not contacting with the head properly, and the wonderful invention of the 8-track cassette could turn out to be the audio world's greatest turkey.
Well, shall I keep you in suspense till next month? No - it sounds excellent. Yes, there is more noise than you would expect on a 4-track - I would put it around the statutory 3dB demanded by the laws of physics, and you can't get better than that. Yes, there are dropouts - about on a par with my Fostex 160 4-track machine, perhaps even a touch less. And no, there is no undue unevenness at high frequencies. I'm amazed. It works!
There is, I must admit, some crosstalk. The built-in noise reduction - which, by the way, is as good as I have ever heard dbx sound - cuts it down during quiet passages. But if you had a high pitched instrument on one track, and a low pitched instrument on an adjacent track, then you would hear the low pitched track breaking through. It's not bad and I must be careful not to make a big thing of this. In comparison, if you were recording live for instance, you would get much more spill between tracks via the microphones.
In conclusion then, eight tracks on standard cassette tape does work, and in the case of the Toa MR-8T it works very well indeed. Don't expect it to sound quite as good as an 8-track reel-to-reel machine - how could it? - but then again, it's not far behind. Many will consider the rackmounting format and the internal monitor mixer ample compensation in terms of cost and convenience. And talking about cost, have you compared the price of a TDK SAX C90 and a reel of Ampex 456 (¼ or ½ inch) recently? Need I say more?
Price £1288 inc VAT.
Contact Toa Electronics Ltd, (Contact Details).
For mixdown (Figure 3), it is possible to use the 'Accessory' sockets (insert points) to feed an effects unit, possibly a reverb. There is no mixing of inputs or outputs for these accessory sockets, so it is a case of strictly one effects unit per track. If you want reverb on four of the tracks, you'll need four reverb units. Monitoring is on headphones.
- Toa MR-8T with a two-group mixer.
Equipment: Toa MR-8T, Seck 12-2 (or equivalent), Alesis Microverb (or equivalent), stereo cassette deck or tape recorder, headphones, power amp and speakers.
Because the MR-8T has its own internal monitor mixer, it means that it can be used by itself or with a simple two-group desk such as the Seck 12-2. Figure 4 shows the recording set-up. A reverb unit with stereo input and output, and preferably an output level control (such as the Alesis Microverb) is used to give overall monitor reverb during recording.
As the mixer has two outputs and the MR-8T has eight inputs, it is better to construct a paralleling cable arrangement rather than to have to replug round the back of the machine every time you record a new track. If you do it like the diagram, the Left output will go to all the odd-numbered tracks, the Right output goes to the even-numbered tracks. All eight tracks can be filled without repatching.
The monitor mix is constructed using the MR-8T's controls. Only level and pan can be adjusted, there are no auxiliary sends. During track-laying, this should not be too much of a problem. The reverb unit can add overall reverb to make the monitor mix pleasant to listen to. The internal switching of the MR-8T will ensure that you hear the Line-In source when you are recording a track, and the Tape signal when you play it back, automatically.
For mixdown, the arrangement is changed to that in Figure 5. The mixer section of the MR-8T is now redundant. Each output is sent to a line input of the mixer, and the two group outputs of the mixer to the stereo tape recorder. If you are using the Seck 12-2, as I mentioned earlier, or a similar stereo mixer, then there will probably not be a monitor output you can connect to an amp and speakers. You will thus have to monitor on headphones, or contrive something to suit your own particular circumstances. I left out the reverb unit on the diagram for the sake of clarity. This time, connect it via the mixer's aux sends and returns.
This system provides all the essentials for 8-track recording, with only two small provisos - no individual control over monitor reverb and headphone monitoring during mixdown. Nevertheless, it's probably the least expensive 8-track system going, other than using the MR-8T as a more limited standalone unit.
- MR-8T live recording
Still using a modestly priced 12-2 mixer, Figure 6 shows the set-up for live recording. The MR-8T's inputs are not sensitive enough for direct input of microphones, so connections have to be made via the channel insert sends of the mixer. Since microphones have to follow this route, keyboards and other line level instruments may as well also. It saves on leads too.
Only one mic input is shown on the diagram. Since the level at the insert point is independent of the fader setting (usually), live mixing can be performed simultaneously without affecting the recording. Appropriate record levels are set on the MR-8T. The insert returns on the mixer are not used.
Review by David Mellor
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