Once the idea of using cassettes for multitrack recording was regarded with acute suspicion. Today the Tascam MIDIstudios are making cassette multitracking a revolutionary art.

IT JUST GOES to show, you never know what's hanging 'til it drops. Only last month, I was lamenting the absence of MIDI on what was otherwise an excellent new mixer from Fostex (the 454), when into my lap (so to speak) falls another piece of equipment which addresses itself quite uncompromisingly to the challenge of MIDIfying the recording process. In the 644, Tascam can not only lay claim to having produced the first of a new generation of cassette multitracker, they have also thrown down the gauntlet to other manufacturers in their adoption of MIDI technology right the way through the recording chain.

Like many ground-breaking designs, it's fair to say there's nothing on the 644 that hasn't previously been available in other forms, from other manufacturers. But never before has so much sophisticated recording technology been packaged together in one box and placed under the control of MIDI - for less than a thousand pounds.

A sophisticated Portastudio? Well how else would you describe a twin-speed tape deck with simultaneous recording across all four channels and full autolocate and rehearse facilities; a complete eight-channel mixer accepting up to 16 inputs with inline stereo monitoring, three-band EQ and two auxiliaries; electronic signal routing with 99 onboard memories and MIDI control of signal muting: built-in MIDI/FSK tape synchronisation, optional remote control... Admit it, this does sound like serious multitracking. Now read on.

NEW TERRITORY

THE LAYOUT OF the 644 is functional and rather businesslike, but a single glance is enough to tell you just how far outside standard cassette multitracker territory you actually are. The mixer, for example, though by necessity quite compact, comes with the sort of control complement you'd expect to find on a stand-alone desk. Alongside three-band EQ with sweepable mid-range, two Auxiliary sends and Pan and Trim controls in addition to the Input level sliders, it features insert points on each channel and balanced XLR connectors for mics on channels 7 and 8.

There's also a Dual section which, as far as I know, is unique amongst multitrackers which have appeared to date. It's basically an in-line stereo monitor mixer which exists alongside the main mixer channels and allows you to set up a mix of previously recorded tape tracks along with instruments you wish to overdub without interfering with the signals being sent to the recorder. During mixdown, the Dual section has a secondary function whereby a further eight inputs are provided, each with its own level, pan and effects send (in conjunction with Aux 2). And it can also, if required, be pressed into service as a third Auxiliary, providing either one stereo or two mono sends for external effects.

Monitoring on the 644 is again entirely compatible with the kind of system you'd expect to find on a separate mixing desk. In addition to listening in on the main signal busses, 1-2 and 3-4 (which, incidentally, are given their own monitor level controls), you can monitor individually or in combination both Auxiliaries and the Dual section. Master controls are similarly comprehensive with faders for the two main busses (the 1-2 slider doubling as the Left/Right stereo fader during mixdown), and rotary controls for both Auxiliaries and for the Dual section. In addition, there are four individual effects returns and a Sum switch for combining Aux 1 buss with that of Aux 2 so that signals may be sent from all 16 inputs to the same effects unit.

AND SO TO TAPE

THE CASSETTE DECK employs three separate motors for play and fast forward/rewind functions, and all switching is logic-controlled so you can go straight from Rewind to Play without pressing Stop. The buttons themselves are light to the touch, yet quite positive in their action. The deck is set up for use (exclusively) with high bias cassettes and offers a choice of speeds - low, 4.75cm/s (standard cassette speed) and high, 9.5cm/s. It also features a pitch control offering some 12% speed variation in both play and record modes.

Unlike many machines, the pitch control does not have a centre detent to indicate the normal speed position. Rather, a switch immediately above it is used to select between Fixed and Vari-speeds, with a third, Ext, position which brings the transport speed under the control of an external device connected to the Serial socket on the rear panel (Tascam's MIDiiZER, for example).

In addition to the customary play, record, pause and wind controls, the 644 also has an extremely effective cueing system - or Shuttle as Tascam refer to it. You enter Shuttle mode by pressing a push button (an LED warns you of its operation) and then cue in either direction by turning a rotary control to the right or left from its centre-detented position. As you may have guessed, a rotary control is used because cueing speed is adjustable according to how far you turn the knob. With a little practise you soon become adept at reeling through the tape at high speed then slowing down to arrive at exactly the spot you want. If you do overshoot, it is simply a matter of turning the control in the other direction and cueing back to the correct point on the tape. Most impressive.

Those of us who have suffered from "multitrackers' finger" over the years will be delighted to hear that Tascam have incorporated a comprehensive autolocator section on the 644. With it you can return to zero, fast forward or rewind to either of two programmable locator points or set up a loop between the two points to enable a section of music to be replayed either manually (by pressing Play), or automatically (by pressing Repeat). This latter feature may also be used in conjunction with a Rehearse facility in which you can program a pre-roll section as well as punch-in and out locations in order to practise drop-ins before actually committing them to tape.

All the autolocate and tape counter functions are used in conjunction with a liquid crystal display which provides a 2x4-digit readout of tape position and locator points. The tape position indicator is, in fact, dual function, and pressing the TRT button converts the display to a read out of Tape Run Time in minutes and seconds. It's not amazingly accurate, but for general timing of songs and estimating whether you have enough tape left on a cassette, it more than justifies its existence.

As you might expect on a machine of this calibre, recording is possible on all four tracks simultaneously - you make your selection from the Record Function buttons immediately above the LCD counter. The corresponding LEDs have three states: "off" to indicate recording is not possible on that track; "flashing" to indicate recording will begin on pressing Record and Play; "on" to indicate recording is in progress.

Noise reduction is dbx and the system performs quite adequately on the 644 with very acceptable hiss levels even on tracks which have been bounced down. Although I was able to detect none of the breathing and pumping effects which were responsible for giving the dbx system a bad name a few years ago, the manual does state that problems may be caused by very low frequency sound being modulated by the dbx circuitry during quiet passages in the music. As it also points out, however, this can be overcome by a little judicious filtering at the input of the mixer (perhaps using the insert socket). And of course, if things become too problematic there's always an off switch for the dbx which you can find at the top left of the recorder section.

"You can send program change commands to MIDI instruments from the 644 - and I'm sure I don't have to point out the creative implications of this."

THE SCENE

MOVING NOW TO what I suppose could be considered the heart of the MIDIstudio - we have the Assignment Board and Display. It is in this section of the 644 that we find the meter displays and also the electronic signal routing facility mentioned earlier. First the meters.

It is possible to switch between two modes: Input, where the meters display signals (post-EQ, pre-fade) from each of the eight main input channels, and Output, where you can keep an eye on the signals from the four tape tracks and also from the four output groups coming from the mixer.

I have to say, the LCD ladders aren't the last word in meter technology and some form of peak hold would have been useful. But having all the metering within a single display is extremely convenient, and doesn't actually take much getting used to. I certainly liked the idea of the input metering being post-EQ and pre-fader as this means you can set up levels even with the channels faders down and also not have to worry about boosted EQ controls causing overloads at extreme settings.

A third button, Scene, switches the display over to the input/output matrix of the electronic signal routing facility of which Tascam seem justly proud. Replacing much of the complex signal switching in conventional recording systems, the graphic display and horizontal/vertical push-buttons make light work of what is traditionally one of the more tedious aspects of multitrack recording. Selecting a line input on channel 3, for example, simply involves pressing Line on the vertical Input column and then 3 on the horizontal Channel/Dual row.

A complete patch comprising all the switching you would have to go through to change from overdub to mixdown mode, for example, can be written as a single Scene. This may then be stored (along with 98 others) and instantly called up - either manually, using the Recall button, or via MIDI using program change commands. In addition to onboard storage (which includes 12 factory programmed patches, incidentally), Scenes may also be stored on tape (immediately before a song, for example) or via MIDI onto a data filer.

MIDI MATTERS

FAR FROM BEING a novel addition to what would otherwise be a well-specified multitracker, it is clear that MIDI formed the basis of the 644's design right if from square one. Thus, we have a full complement of MIDI sockets on the rear panel - In, Out and Out/Thru - the latter being normally used as a secondary Out port, but acting as a MIDI Thru during saving operations. Of course, the existence of MIDI Out sockets will have no doubt alerted you to the fact that you can send program change commands to MIDI instruments from the 644, and I'm sure I don't have to point out the creative implications of your recorder being able to tell your sequencer what to do (or where to go, for that matter...)

More conventionally, MIDI commands can be sent from your sequencer or keyboards to the 644, and, as I have already outlined, this can be used to recall Scenes. Even more interesting though, is the facility for using MIDI note commands to mute or unmute any of the eight main input channels (as on Tascam's MM1 MIDI mixer - reviewed MT, November '89). Using this you can take channels in and out of the mix with considerable accuracy. In fact, you're limited only by MIDI timing delays which may occur - and under most circumstances these could be discounted.

When you think about it, the channel muting and the Scene recall functions offer a not inconsiderable level of automated mixing. Not only that, but all the associated MIDI data can be stored along with your conventional sequencer information, so there need be no going back to a song after 12 months and wondering just how the hell you mixed it the first time round.

Also, with a bit of forward planning, you should find that you can optimise the use of your four audio tracks using MIDI. On any occasions where two or more instruments don't coincide in a song, you can assign them to the same audio track and simply use the channel mutes to take them in and out of the mix. You'd be limited to the same EQ settings, but provided there is enough space between instruments, it shouldn't be too difficult to tweak the necessary knobs on mixdown. After all, given the level of automation possible, your hands won't have much else to do.

It's in the field of tape synchronisation, however, that MIDI is likely to see most regular use on the 644. As indicated at the beginning of this review, the system included here is the MIDI/FSK type (adapted from Tascam's own MTS30 design) which converts MIDI clock information from your sequencer (for example) into an audio tone called FSK (Frequency Shift Keying) which is then recorded to tape.

Unlike conventional time code, where you have to start from the beginning of a track each time you want to reach a certain point, FSK contains song pointer information which constantly updates your sequencer so that no matter where you start, it gets itself in step with the tape at the right point in the song. You sometimes have to wait until the next song pointer comes along, but in practise, lock-up never takes more than a second or two. Certainly, I encountered none of the traditional problems associated with tape striping and had the 644 and my sequencer locked together at my first attempt.

"When you think about it, the 644's channel muting and the Scene recall functions offer a not inconsiderable level of automated mixing."

ASK THE PANEL

THE 644's REAR panel packs a tremendous amount of connection hardware: quarter-inch jacks for all 16 inputs, effects returns, auxiliary and dual outs; XLRs for balanced mics on channels 7 and 8; stereo jacks for the channel insert points; phonos for tape outs, group outs, monitor outs and in and out connection of an external sync unit (if this is required). Additionally, there are the three MIDI sockets, a 15-pin serial port for the connection of the Tascam MIDiiZER (or an external computer), and a special 8-pin DIN socket to allow connection to Tascam's RC88 remote control unit which duplicates the auto-locator, rehearse and punch-in facilities on the 644 itself. Last, but not least, we have the on/off switch and the all-important power supply socket - the 644 is operated from an external 10V supply.

VERDICT

AS WITH ANY complex piece of audio gear, by the time you've gone through all the facilities it includes, how it actually sounds can sometimes seem like rather an irrelevance. After all, a company like Tascam wouldn't pack all those features into a machine like the 644 if it didn't perform, would they? Well, no, they wouldn't actually, and the 644 MIDIstudio's audio performance has obviously been designed to do full justice to its capabilities in all other areas.

Noise and hiss levels are extremely low (probably about as low as the humble audio cassette can go at this stage in its career) and problems like crosstalk can, with a little care and attention, be virtually eliminated. Unlike many two-speed multitrackers I've come across, I found I could get very creditable results at the lower speed on the 644, although the high speed setting would have to be recommended if you intended bouncing any of the tracks as this involves a slight loss of quality. But that's only to be expected.

Getting signals onto tape via the mixer was similarly trouble-free; noise levels were quite acceptable even at relatively high settings of the Trim and EQ controls - though of course, being able to mute channels when they are not required really does help in this respect. Drop-ins didn't pose any real problems either, though I did notice a slight delay before recording came into effect. It is however, fairly easy to compensate for this.

You get the feeling with the 644, that, as new as it is, there's a lot of tried and trusted design work gone into it, particularly in respect of the mixer electronics and the cassette mechanics. It has that air of quiet efficiency which surrounds most high-quality equipment. There are plenty of nice touches too: two headphone sockets located in a recessed panel under the front edge of the unit so that the plugs don't protrude; a padded arm rest at the bottom of the unit; and the Dual section colour-coded in grey to distinguish it from the rest of the mixer.

The instruction manual is excellent. No "loose" translations, no indecipherable spelling, no operations left uncovered or changed at the last minute and not included. It's rather a dry read, but it contains everything you could want to know about the 644 and you can't reasonably ask for more. Oh, and it has an index at the back, so perhaps our constant badgering of manufacturers on this point might be getting us somewhere after all.

So what can we conclude about the first MIDI cassette multitracker? Well, a Portastudio it might be, but this is the kind of technology which is going to prove highly appealing even to those who aren't interested in multitracking on a budget - the traditional market for this type of unit. The 644 and its big brother, the 688, are bound to attract a lot of interest from those who like the idea of a complete recording system packaged in one neat box and given the power of communication with the rest of the equipment they already own. And I certainly have no hesitation in including myself amongst that group.

As anyone with any serious interest in hi-fi will tell you, packaging equipment together within a single box inevitably leads to compromises. Where convenience becomes a concern, quality and flexibility inevitably suffer - well, not on the 644 they don't. In fact, I'd go as far as to say it's a better system for being a complete unit than would be the case if it were assembled from discrete components. Like any machine, it isn't perfect; there are always extra facilities one would have like to have seen included. But lines have to be drawn somewhere and keeping it below the thousand pound mark must have entered the equation at some point. And as far as I'm concerned, the line for the 644 was drawn a long way beyond that which we could have reasonably expected for what is, after all, the very first MIDI Portastudio.

Having read the reviews in other music magazines, I think I'm justified in saying that they have done Tascam something of a disservice in their coverage of the 644. Though the machine has been given a favourable response in all quarters, I've yet to see any real mention of the significance of the 644 as a development in MIDI technology. As far as I'm concerned it is a machine of immense importance for users of hi-tech MIDI equipment and that must include just about every reader of MT.

In conjunction with one of the better computer-based software sequencing packages around at the moment, the potential of the 644 is quite awesome and extends well beyond its modest four-track format. Unless you're involved in multitracking more than two or three non-MIDI instruments such as voices and guitars (or simply don't have many MIDI instruments at your disposal), the limitations of four-track recording become something of an irrelevance. If you do need extra audio tracks, you could always turn your attentions to the 688 (as I hope to be doing shortly), but either way, you cannot consider moving into multitrack recording without considering one or other of these machines. Highly recommended.

Price £869 excluding VAT.

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