Scarcely a month goes by without a new MIDI-to-tape interface unit being released into what is by now a crowded market. The reluctance of sequencer manufacturers - both hardware and software - to include some sort of timecode or sync code processing into their units, other than of the most basic kind, means that there are a large number of prospective purchasers of such units, and a wide variety of models from which to choose. The Musicsoft Syncman provides yet another choice in this area, and - as we shall see - offers a very acceptable performance and range of facilities for a modest price.

Less common are units which allow MIDI data to be recorded directly onto tape, such as the new Musicsoft MIDIman? On the face of it, the question arises of why anyone should want to record MIDI data onto tape, rather than laying down the audio signal that it indirectly generates (on a synth, sampler or drum machine) onto the magnetic medium? And surely MIDI data, like computer data, is better suited to being stored on floppy disk than on audio tape? But one of the benefits of advancing technology, and the existence of small manufacturers willing to be creative in their science, is that potential users can think up their own ideas on how to use such a machine. The Musicsoft MIDIman could open up valuable new avenues to explore.

But let's start with a more familiar type of unit, with the Musicsoft Syncman.

SYNCMAN

First, a brief justification for the existence of sync-to-tape interface units. Why it should be that most sequencers do not have built-in tape sync capability is a mystery to me, but this is the way things are, and unless the sequencer of your choice has a proper tape sync function, you will need to acquire a unit that will carry out this function if you want to enjoy the full benefits of multitrack tape. (Perhaps I should mention that some sequencers include a tape sync facility which requires the user to start the tape from the beginning of the song each time to maintain proper sync. By 'proper' tape sync, I mean the ability to start the tape anywhere in the song and have the sequencer follow the tape exactly.)

Syncman provides two means of syncing to tape, via SMPTE/EBU timecode or Song Pointer Sync - the latter is Musicsoft's own system, and is similar to that used by the J.L. Cooper PPS1 sync unit [reviewed SOS Nov 1987]. One system or the other can be used, but not both. SMPTE/EBU timecode is, as you are probably aware, a time-of-day code striped onto the tape. This is ideal forgiving positional information (ie. what point on a tape has been reached) to a reader, but it can contain no direct information about the tempo of a piece of music or the location within it. This information must come from a sync unit, which can be programmed with a 'map' of how song tempo and position relates to timecode values. Unusually, Syncman does not actually have these facilities, but to compensate it supports MIDI Timecode which, with a suitable sequencer, enables all of the same chase functions to be carried out, as I will explain. Song Pointer Sync takes a different approach to the sync problem. Rather than recording time-of-day data, it records tempo and song position data that it can translate directly back into MIDI clock pulses and Song Position Pointers.

Syncman comes in the form of a small metal box with a minimum of controls on the front panel, MIDI In and Out sockets, Tape In and Out jacks, and also a socket for a 9-volt external power supply. At this point I will include my standard moan about external power supplies, in the hope that manufacturers realise that they do not enhance the attractiveness of any piece of equipment. In this case the attraction is lessened even more by the fact that a power supply is not provided with the unit. Unfortunately, the manual does not state the diameter or polarity of the correct power connector, nor the current consumption - an omission that really should be corrected.

The front panel features two LEDs, six DIP switches, and a large button to initiate the process of writing a sync code to tape. DIP stands for 'Dual In-line Package', but you may read it as 'fiddly, to be operated infrequently with a small screwdriver'. To save a second description later, I'll just say that MIDIman looks exactly the same as Syncman, although the functions of its switches are different.

These DIP switches are used to select the basic modes of operation of Syncman. Two are used to specify the SMPTE/EBU format to be used, one switches between SMPTE/EBU and Song Pointer Sync, one selects Direct Lock operation (a sync system used by the Performer sequencing software for the Apple Macintosh), and the final two select Duplicate and Merge functions.

SPS OR SMPTE/EBU?

The procedure for using Song Pointer Sync (SPS) goes like this. The basic music tracks are recorded into your sequencer, together with any changes in tempo. When the overall structure of the song is complete and you want to lay some tracks to tape, you are ready to record the SPS code. The MIDI output from the sequencer is fed to Syncman, which converts the stream of MIDI clock pulses that constitute the tempo information, and the MIDI Song Pointers, into a tone which is recorded onto one track of the tape.

Thereafter, the SPS tone on tape may be replayed into Syncman, which converts it back into MIDI clock pulses and Song Position Pointers to drive the sequencer. The result is that you can shuttle back and forth along the tape and the sequencer will always know which part of the song it is meant to be playing. It is a neat and pretty well foolproof system, and one that is compatible with all but the most basic MIDI sequencers and drum machines.

To use Syncman's SMPTE/EBU timecode facilities, rather than SPS, you need a sequencer that understands MIDI Timecode (MTC). People have been talking about MIDI Timecode for quite some time now, and its specifications are established, but not very much has been done about exploiting its potential to date. Basically, it is a way of sending SMPTE/EBU time-of-day data down a MIDI cable, which therefore provides a means by which a sequencer can synchronise to tape or another MTC-compatible MIDI device.

"Whilst the applications for Syncman and similar units are well known and obvious, those for a device such as MIDIman are rather harder to imagine."

This is actually very useful, because if a manufacturer wants to design a sequencer to a cost that precludes the inclusion of a SMPTE/EBU reader - which needs relatively expensive chips and circuitry - he can include MTC capability at the lesser expense of a bit of extra software. The sequencer will then be able to sync to SMPTE/EBU via a unit such as Syncman, which will translate timecode into MTC. This is how it works in practice...

I used Syncman in combination with an Akai ASQ10 sequencer, which despite having its own SMPTE/EBU reader can also sync to MTC - I used it in this latter mode of operation. Following my normal practice, I striped the whole length of a tape with 25fps EBU timecode, generated by Syncman. For your information, 24, 29.97 and 30fps codes are also available on Syncman, and can be used with MTC. All that the ASQ10 then needs to know to sync to the tape is a start point for the song (in hours, minutes, seconds and frames), and it will lock in both record and play modes to the MTC generated from the timecode by Syncman, starting at any point on the tape. The absence of internal tempo and start point facilities on Syncman is irrelevant if your sequencer can understand MTC, and if it doesn't you can use SPS, which for most purposes is just as good and only slightly more fiddly.

Other features of Syncman include MIDI Merge, which enables data received at Syncman's MIDI In to be combined with that generated internally, and the merged data transmitted from MIDI Out. This allows overdubs to be made into the sequencer while synchronising to tape - an essential feature. Duplicate allows a previously recorded SPS or SMPTE/EBU stripe to be duplicated onto another tape recorder, avoiding the loss of quality that simple tape-to-tape copying would involve.

In short, Syncman works, it shows what MIDI Timecode can do, and it doesn't cost a lot. Unless you need the more specialised functions of, say, a FriendChip SRC/AT, then it should prove entirely adequate for synchronising your sequencer to tape.

MIDIMAN

MIDIman is a rather different kettle of fish to Syncman. Whereas the applications for Syncman and similar units are well known and obvious, those for a device such as MIDIman are rather harder to imagine. But let's start by seeing what MIDIman can do, leaving the question of applications for later.

Connect the MIDI Out of your synth to the MIDI In of MIDIman, and the Tape Out of MIDIman to a tape or cassette recorder. Put the tape recorder into record mode, hit the Write button on MIDIman and start playing your keyboard. All the MIDI data you are now generating will be converted into an audio tone which is recorded on the tape. Reversing the procedure, you can play the tone from tape back into MIDIman and the MIDI data that you recorded will be reproduced at MIDIman's MIDI Out. Yes, it is just like recording into a sequencer, except that the data storage medium is magnetic tape rather than RAM chips.

If you know a little about MIDI, this ought to be raising the question 'is this possible?' in your mind. After all, the MIDI data transmission rate is over 30kHz, yet the highest frequency you could reasonably expect a tape recorder to reproduce faithfully is more like 18kHz, perhaps less if it has seen heavy use. Surely this limits the amount of data that can be stored in real time by this method?

As it happens there is a limit to MIDIman's capabilities and, to be fair, Musicsoft make this quite clear in their manual, and on a separate sheet of paper included in the package. MIDIman itself limits the rate of information transfer, so that it will fit into the bandwidth of an average tape recorder. Send too much MIDI data in a short period of time and that data will be spread out over a period of milliseconds to ease the load. What this means in practice is that MIDI's inherent tendency to convert chords into quick arpeggios is made approximately four times worse.

As a result of this limit on the rate of data transfer, although it is quite practical to record one MIDI channel's worth of playing through MIDIman onto tape, complex multi-channel sequences are made audibly less accurate. I should also mention that, as well as the slight timing inaccuracies, the resolution of MIDI Velocity values is coarsened, reducing the 'subtlety' of the playing.

"Song Pointer Sync is a neat and pretty well foolproof system, and one that is compatible with all but the most basic sequencers and drum machines."

But having said this, and being aware of the physical constraints imposed by transfer to the tape medium, this system does work - which is a bit of a feat in itself.

MIDIman has several features designed to help cope with these problems. Two bandwidth settings are available for the tape tone, one suitable for cheap cassette recorders and the other for higher quality machines. The first uses a fairly low frequency 'carrier' tone for optimum reliability, but tends to spread notes out as mentioned above. The high bandwidth setting gives greater accuracy, but requires a decent cassette player or a reel-to-reel machine. I used a Sony Professional Walkman with ferric tape at the higher bandwidth, and found no indication of tape dropout and no audible inconsistencies.

To improve the accuracy of the all-important drum and bass tracks, two MIDI channels are given priority over all the others. Top priority is given to Channel 10, which most people use as their drum channel; second priority goes to Channel 1, which you should use for bass or whatever your next most important channel is from a timing point of view. All other MIDI channels just take their chance in the melee.

One major consumer of MIDI bandwidth, as sequencer users will already know, is Aftertouch information. If your master keyboard has its Aftertouch option selected - or if Aftertouch is a permanent feature - you cannot help generating reams of data that may either clog up your sequencer's memory or force MIDIman into producing timing inaccuracies. The solution to this problem is to set MIDIman's Aftertouch filter switch to 'off', whereupon the Aftertouch data will be ignored.

Besides these essential features, MIDIman has several other facilities that qualify as merely useful: a MIDI Merge function allows you to mix MIDI data from a keyboard with the data that is being read from tape; recordings made with MIDIman can be copied using the Duplicate function, which reshapes the pulses to ensure a clean signal; System Exclusive dumps can be made to tape; and MIDI clock pulses can be recorded to tape, which offers the possibility of using MIDIman as a basic tape sync box. On the face of it, System Exclusive dumps could create problems for MIDIman due to the high data transfer rate involved, but a 33K RAM buffer allows even relatively large dumps to be made to tape.

USES?

When I first heard about MIDIman, the first possible use for it that sprang to mind was in archiving MIDI data onto a multitrack tape along with the audio tracks - one tape track could be devoted to the MIDI data for the music on the other tracks. This would mean that the MIDI data would always be available on the same medium as the audio, with no floppy disks to lose. In addition, it would mean that you wouldn't need to have the original sequencer to replay the programmed parts. It is an interesting thought.

The snag is that MIDIman, in my opinion, does not work to the degree of accuracy that would be required, unless it was a very simple track, and even then some Velocity resolution would be lost. It could be useful for an emergency backup, but I don't see how it can replace floppy disks.

A more valid use for MIDIman might be as a helping hand for the gigging musician. Suppose you use a computer sequencer at home and want to use sequenced tracks on stage. I am not sure that dragging along an Atari ST with keyboard, mouse and monitor is altogether a good idea. But taking MIDIman and a cassette deck to the gig sounds a lot more appealing - simply transfer all of the sequenced parts to cassette. MIDIman certainly performs well enough to fulfill this task. As another possibility, I fully expect buskers on the London Underground to become MIDIman-equipped before long.

VERDICT

Musicsoft have come up with one very useful box and one very interesting one, both at reasonable prices. MIDI-to-tape interfacing has indeed come a long way since the early days of simple sync tones. Timecode synchronisation is well developed and units such as Syncman can now bring the cost down to sensible levels, where professional sync-to-tape facilities are within the grasp of the average home recordist. It's good to see that Musicsoft have taken advantage of MIDI Timecode on Syncman, and we can only hope that its inclusion on units such as this will force sequencer designers and manufacturers to include MTC as standard, even in their least expensive models.

Recording MIDI data to tape is a fascinating concept, useful to the gigging musician and perhaps to anyone who has a MIDI system and a headful of ideas. MIDIman has limitations, but within these it works perfectly well and could point the way to other MIDI-to-tape interfacing possibilities.

FURTHER INFORMATION

£185 (each) inc VAT.

Radius International Ltd, (Contact Details).