Or how to get the best from your electronic instruments by syncing them together. The first part looks at syncing hardware to tape.

Recording with modern electronic musical instruments like drum machines and sequencers is now commonplace, and whether you have four-track or 48-track recording facilities, you can't deny that more hit songs are written, demoed, recorded and performed with their help than ever before.

The modern musician's language is full of an odd assortment of figures and letters - MSQ700, SBX80, KPR77 - which can be dropped casually into the conversation as a form of musicians' one-upmanship to embarrass pals who are not so well up on the latest trends but which sound like gibberish to the non-muso.

Now that we've got used to the terminology (interface, cassette dump, synchronisation - well explained in Ian Gilby's review of the Mini Doc in E&MM August '84 - MIDI and so on), the world is at our feet. Well, perhaps not quite.

After all, it's what you do with the technology that counts. However, one thing that has proved to be of great benefit to the musician - whether he or she records on a home studio set-up or at one of the nation's top studios - is the sync-to-tape facility.

Sync and Tape Sync

Modern drum machines and sequencers have a built-in clock determining the speed at which the machine will run. This clock is in fact a series of regularly-spaced pulses, and the time base for each unit is defined by the number of pulses-per-beat (crotchet). Incidentally, it's worth mentioning here that the Americans have their own name for a crotchet - they call it a 'quarter-note' based on the fact that if you're playing in 4/4, a crotchet will be equal to one quarter of the bar (similarly, quavers become eighth-notes, semi-quavers become sixteenth-notes, and so on).

Now, if your drum machine or sequencer has a socket labelled Sync In and one labelled Sync Out, or alternatively one socket labelled Sync In/Out with a switch to select one or the other, you'll be able to drive external devices with your machine's clock. Alternatively, you can override your machine's internal clock with a signal from the clock of another machine. In order for this to work, though, both machines must have the same time base (ie. utilise the same number of pulses-per-beat), otherwise they will not run in time with each other. For instance, if one machine's time base is 96 pulses-per-beat (eg. Oberheim) and the other's is 48 (eg. LinnDrum or Roland MC202), the latter will run at twice the speed. There are, however, units available which 'translate' from one timebase to another. Examples are the Doctor Click and Mini Doc devices, both of which, incidentally, will also read sync codes off-tape.

If your machine has a sync-to-tape facility it will have tape sync output and input sockets, and these supply and receive a processed version of the clock signal (sync code) with the result that your machine's code can be recorded onto tape and used later as the recorded code to run the machine.

There are a number of reasonably-priced products with this facility available. The Roland MC202 Microcomposer was the first budget machine with built-in tape sync and this has been around for a couple of years, but other manufacturers have been rather slow on the uptake of the tape sync idea, regarding it as an option only to be made available on more expensive models. Machines that come into this category include the Roland TR909 and MSQ700, Sequential Circuits Drumtraks (which has a switchable sync out of 24,48 & 96 pulses-per-beat), E-mu Systems Drumulator (five trigger conversion), the Oberheim DX and DMX, Korg KPR77 and Yamaha's new RX series drum machines.

A number of units which aid drum machine, sequencer and multitrack synchronisation are now available in addition to the Dr Click and Mini Doc already mentioned. The Korg KMS30 MIDI Synchroniser is another unit which aids sync-to-tape among its many other functions, while a very modestly-priced unit made by MPC called the Sync Track (see review, E&MM May) allows you to convert the sync output of any machine into a form whereby it can be recorded onto tape. It also reverses the process, ie. reads the code off-tape and translates it back into a clock pulse. This unit was designed primarily for use with Roland Products not provided with tape sync, but with the help of the instruction booklet supplied, you can use the Sync Track with any machine having sync or clock outputs. Incidentally, some retailers are offering this unit with the Hammond DPM48 drum machine as a package deal.

Recording the Code

The sync code has to be recorded on its own track, and most machines will give you a line level output which should be recorded onto tape at the level recommended by the manufacturer. As you'd expect, advice varies, and where the manual for a drum machine like the Linn (which generates its own code) recommends a level of -3dB, the designers of the Sync Track suggest you use a level between -3 and -7dB. By the way, the Linn manual also recommends you bypass any noise reduction system.

It's certainly worth experimenting with levels until you find out what suits your recording setup best, but be prepared for a certain degree of crosstalk onto adjacent tracks caused by the nature of the sound of the code. Problems may arise when attempting to retrieve the code off-tape if you have dirty heads on the recorder, and well-used tape is prone to dropouts which certainly won't aid recovery. In addition, if you're using a track on the edge of the tape, bad head alignment could cause difficulties. Finally, highly transient sounds, such as drums, recorded on adjacent tracks have also been known to interfere with the smooth operation of the code.

Using the Code

With your sync code successfully recorded onto tape, you can, on playback, run several machines at once off the one code. For example, if you put the code down from a Roland MC202, on playback you could use the 202 synced up to a TR808 drum machine (providing handclaps, say) and use 808's trigger outputs to drive the clock inputs on the arpeggiator of a polysynth. In the studio recently we used a TR606 Drumatix with a Sync Track into a BBC B computer via an Electromusic Research Miditrack Composer interface box, using the MIDI Out of this to run a Yamaha DX7. As we had plenty of tracks to play with, but only one DX7, we ran off the programmed sequence several times, using a different voice each time to obtain a layering of sounds, but you could get the same effect rather quicker if you linked several DX7s together!

Basically, there are two main advantages of using a sync-to-tape system. The first is that you are able to change or add to your sequence or drum pattern at any time during your recording without having to start from scratch, so that, for example, you can leave writing the drum part till the end if you wish. The other advantage is that if you have a problem with shortage of recording tracks, you can run all your drum machines, sequencers, handclappers et al perfectly in sync with the rest of the track through separate channels on a mixer off the one sync code track, EQing and adding effects as you please, without having to record them at all. And as a bonus, this also means they're recorded first-generation onto the master tape when you mix.

One drawback to this method of tape syncing (it's known as the FSK system, incidentally) is that as a rule it doesn't allow you to drop-in a sequence (or whatever) during a piece. For the machine to run in time with the track, it's necessary to start from the beginning each time. The MPC Sync Track gets over this to some extent by providing a Run/Stop switch that enables you to start the machine manually at any time during the track, though this is a bit tricky to accomplish.

For the ultimate in tape syncing, look no further than the newly-announced Roland SBX80 Sync Box, which generates SMPTE (Society of Motion Pictures and Television Engineers), a code originally devised for use in the broadcasting and film industries for syncing soundtracks to film. This machine (amongst many other things) will allow you to drop-in in the middle of your track: you could also use it to sync a video to your demo!

Summing Up

With the price of hardware incorporating tape sync facilities dropping all the time, and the availability of helpful gadgets like the Mini Doc and Sync Box to sort out the major headaches of incompatibility between gear from different manufacturers, the future is looking rosy for modem musicians, be they pro, semi-pro or amateur. The system is of particular benefit to four- and eight-track studio owners who find themselves running short of tracks, as they're now able to designate one track to the code and run sequencers, drum machines and so on without the signal degradation that bouncing-down invariably causes.

Who knows? Maybe one day we'll all be doing our demos on two-track - one for the code and one for the vocals.

RRPs (inclusive of VAT) for products mentioned above are as follows:

MPC Sync Track - £39.95, contact MPC Electronics Ltd, (Contact Details).

Roland MC202 - £235, SBX80 - £900, MSQ700 - £950, contact Roland UK Ltd, (Contact Details).

Garfield Electronics Doctor Click - £1987, Mini Doc - £525, contact Music Lab Sales, (Contact Details).