The seminal Californian synth company Oberheim (who sadly seem to have gone into liquidation more times than a daiquiri in a Sunset Boulevard gin-joint, but who also, thankfully, have guitar giants Gibson as their new knight in shining armour), are soon to release the OBMX — a new analogue synth module. Analogue instruments, it seems, are still alive and kicking in the digital age.

Prior to this, the last dedicated analogue synth made by a major keyboard manufacturer was the Cheetah MS6, released in 1988. The last new and dedicated monophonic analogue synth made by a major keyboard manufacturer was the Roland SH101, which hit the streets almost a decade ago in 1982.

Before the faxes start flying, yes, there was a thing called the EVS1 which was cobbled together from a load of old radio spares in some Hong Kong backstreet in 1989, and the British OSCar appeared in 1983 (OSC, correct me if I'm wrong, didn't make anything else though), and it's true that in countless bedrooms and garages throughout the land monophonic and/or analogue synths are still being soldered together, but...

But, the point is that in spite of MIDI, FM, LA, AI and other synthesis techniques, sampling, DAT, digital audio workstations and Lord knows what else, old analogue synths are still with us. Watch Top Of The Pops, venture into any studio, stage, or rehearsal facility, and you'll still see analogue equipment being used, long after the Yamahas, Rolands, Korgs, and Emus of this world seem to have abandoned the cause.

In the hard world of mass market 'commercial' keyboard products, analogue is now simply used as a descriptive term applied to style, as in "analogue type editing parameters" or "...warm analogue samples...". So does analogue's future only lie in vague associations with its past? Is the current glut of SH101 and CS80 usage simply faddism? Would anyone outside a university research facility buy a new analogue synth today?

Basically, what is the position of analogue synthesis in the 1990s?

WHAT DOES 'ANALOGUE' MEAN?

Analogue refers to "a circuit that produces a continuously changing electrical signal" according to Steve de Furia in his book The Secrets of Analog and Digital Synthesis. It is "that which is continuous in nature, as opposed to being defined as a series of discrete numbers" says Craig Anderton in the Electronic Musician's Dictionary. It is a quantity that can have "absolutely any value" says RA Penfold in his book Synthesizers For Musicians. An analogue synthesizer is "an electronic instrument whose sounds are produced as result of changing control voltages", as I once put it.

None of these definitions exactly leap off the page for the average musician I fear. Whether a definition exists that is fathomable yet nonetheless remains accurate I can't say, but, together, such explanations will still serve to inform the non-technical that analogue synthesis is clearly not an exact science. Rather it is a question of variable input voltages (with all the fluctuations that invites) persuading an oscillator to kick out different pitches, or an amplifier different volumes; it is a question of overdriving filters, of sample and hold circuits, of being able to deliver a pulse wave in a theoretically limitless number of 'widths.' It is a world of relative randomness, and of rawness.

WERE OLD ANALOGUE SYNTHS THAT GREAT?

In order to find out why, and if so how, analogue synths can live in today's digital domain it is sensible to look at why such instruments died out in the first place. Analogue died for a number of reasons, and most can be traced back to some form of cost/value judgement, eg. regarding reliability, parts, labour, computer compatibility, data storage capacity etc.

Put simply, manufacturers realised that they could give us more for less if we all went digital, and as digital synths, most notably Yamaha's DX7, arrived, appearing to offer unlimited scope for sounds, and unrivalled sound quality and stability, things that we now perceive as being virtues, such as immediacy, humanity, and warmth, were viewed with comparative disdain.

But was it all fun and frolics with analogue synths, innovative new sounds a-plenty, all of them rich and vibrant? If I remember correctly, no, it certainly wasn't. 'Synthetic', a decidedly pejorative term, was the adjective most commonly used to describe the performance of the average analogue synth. Those tinny strings, that metallic brass, those clunky pianos. Bass was probably the only sound type regularly given active praise in the analogue era. And as for lead line sounds... listen to any early Genesis or Yes record if you want a quick reminder of the 'elephant in labour' racket that used to permeate the grooves.

Before the days of programmability there was always the problem of getting, and then recreating, a sound. Many's the session that slid into suspension while the luckless keyboard player beavered about trying to maintain his sound long enough for a complete take, never mind try to recreate the wretched thing should an emergency repair become necessary the following day.

Then there was tuning (or rather there wasn't), along with sundry other manifestations of unreliability like perennially dusty, crackly pots, and assorted output hums, buzzes, and hiss.

Finally, there is one myth that needs exploding; the one that has grown up about analogue synthesis being 'simple.' This is like saying "apples are green", or "cars are driven too fast".

In its most basic form analogue synthesis is fairly easy to understand. True. There again, so are the principles behind FM synthesis, or most types of synthesis in fact. But what does this mean in practice? Precious little, if you have ever tried to fathom out an Oberheim Matrix 12, or even some of the more in-depth aspects of a Prophet 5, and certainly any modular synth.

Analogue synthesis can be every bit as frustrating and impenetrable as a digital system. In fact, when you consider that your starting point is likely to be a raw waveform as opposed to a nice sample that sounds half-way decent already, pure analogue can be the most complex and tiring system with which to work.

It would be dangerous, then, not to temper one's expectation of analogue with large dollops of realism.

TODAY'S ROLE FOR ANALOGUE

Having offered the above stern words of warning, there does remain a genuine (as opposed to faddy) place for old analogue synths in the current environment.

Although at first there may appear to be two chief justifications — sound, and easy programming — in reality they are but two halves of the same argument. Analogue programming is relatively straightforward: we see a parameter, we adjust its value, we hear at least the type of result we expect.

Analogue sounds thus tend to be less precious, in every sense, than their digital counterparts. The sounds themselves may be less precision-tooled, but people tend to use them in a more personalised way. And they do so because they can.

In spite of the oft-repeated story about 90% of the Prophet 5s that came back for service having their factory presets still intact, 1991's preponderance of 'off-the-shelf' sounds would have been greeted with hoots of laughter back in the 1970s.

Today, when not only do most synths sound the same anyway, but everyone has access to the same (and in digital this does mean the same) patches as well, the injection of some form of bespoke programming is invaluable.

MONOPHONIC SYNTHS

Monophonic synths were the instruments that kicked the whole business of synthesizers into life. Synthesizers were originally designed as producers of weird noises and explorers into the sonic unknown. Their subsequent application as 'regular musical instruments' came right out of the blue.

Consequently, for the first few years the fact of instruments being monophonic (able to produce just one note at a time) was not viewed as a being a particular disadvantage. (You want to play chords and stuff? Well, buy an organ, or a piano...) By the time monophonic synths started to appear as portable, playable, affordable items (the MiniMoog was the first of this generation of instruments), they had three main uses in pop/rock music: lead lines (solos), bass, and effects.

For solo and bass work the important features were power, and an ability to cut through, determined by such things as the number of oscillators per note you were being offered, and the type of filters the synth had. For sound effects the best instruments were those that offered multiple routings, along with features like sample and hold, cross modulation, and ring modulation — features that steadily dropped off the bottom of the ladder as time went by.

Today's application for monophonic synths has changed remarkably little. Although synth solos, as such, are almost unheard of, lead lines and riffs are still needed (both played and sequenced), and synth bass playing remains perfectly valid, as are sundry sweeshes and swooshes, blips and blurrs that fall into the ragbag called effects. But one question remains: why do we need monophonic synths to cover these territories?

In fact, we don't. We can, and do, use regular modern synths for all the above tasks and more. But you'll be hard pressed to find a bass sound to match the depth of a Moog (Mini, Multi or Micro) or a Roland SH101. You'll do well to get just the right degree if tinniness on a modern synth for one of those 16th note sequencer parts. In fact, you'll do well just figuring out how to produce a filter sweep on most current synths!

POLYPHONIC SYNTHS

Purists mark the demise of synthesis by the day polysynths first appeared on the scene. Considering that one of the first examples of the type was the dreadful Moog PolyMoog this viewpoint is not altogether surprising.

The first batch of generally playable instruments — Oberheim 4/8 voice, Prophet 5, Yamaha CS80, Roland Jupiter 4 — were either straight 'polyphonised' versions of mono synths, or little more than 'synthy' types of organ.

The analogue poly reigned between 1978-84, during which time the tumbling cost of chips resulted in the sub-£1000 instrument and a consequent expansion of the market. During this time the synthesizer's role was slowly redrafted from that of solo/bass/effects producer to the all-embracing 'orchestral' type of instrument it remains today.

About the only 'real' instruments that the early analogue polys could ape were organs and, to a lesser extent, flutes and woodwinds. Everything else was either a near-joke (pianos, guitars, percussion) or employed strictly as a 'synth' version of an acoustic sound, as in synth strings, synth brass etc.

The analogue poly was best suited to producing what we today term 'pad' sounds — sounds of varying type and colour used for interesting but not too obtrusive backing.

In the days before such concepts as MIDI and multi-timbralism, polyphony simply concerned the number of voices you could physically play in real time. The norm was between five and eight voices.

In spite of today's obsession with multi-timbralism, as any semi-serious user knows only too well all synths loose something in this mode of operation. An M1 for instance: take a Program, put it into a Combination, copy the effects across, do what you will... something is invariably lost in the translation.

This being the case there is much to gain from having some relatively low-cost older instruments in your armoury, thereby avoiding having to tie up your main instruments on one sound. This can be particularly helpful on washes and pads, or textural sounds.

INTERFACING WITH THE MODERN WORLD

Although analogue synths have been made with MIDI, a large number (including all but the OSCar in the monophonic class) predate MIDI's inception in 1982.

Prior to the adoption of MIDI synths were rarely hooked up together. But when they were, they used either the manufacturer's dedicated interface (Roland's DCB, Yamaha's Key Code, etc.) whenever such had been offered, or else they used their CV and Gate connections.

The Gate connection governs timing — the duration of a note. The CV (Control Voltage) connection, normally a jack socket, deals with pitch, the standard relationship between voltage and pitch being 1 volt per octave (eg. 1 volt = 110Hz, 2 volts = 220Hz, 3 volts = 440Hz etc. — remember, an octave jump corresponds to a doubling of frequency). Not all synths conformed to this however, so complete compatibility was far from guaranteed.

To link up monophonic synths via CV and Gate connections was a bit fiddly and far from foolproof, but relatively straightforward. Linking up polyphonic instruments, however, becomes fairly impractical.

In order to connect CV/Gate based synths to the modern world of MIDI you have two choices: buy a MIDI-CV convertor box, or install a MIDI retrofit on the instrument itself. A box has the advantage of flexibility (you can use it on different instruments), and the retrofit the advantage of convenience.

ANALOGUE SAMPLES

One way around the problems of interfacing with older equipment is to use samples of analogue synths. This is not, however, the perfect solution, for the simple reason that by sampling a sound it is captured, frozen in time, which thus negates part of the transient beauty of analogue synthesis. The process of sampling analogue synths is relatively straightforward, although some re-tuning may be necessary. If you cannot procure the particular instruments you want to sample, CDs can come to the rescue (eg. the MasterBits Sampling Collection, Hit Music Productions HitSound range).

MODULAR/PATCHBAY SYNTHS

Although the major manufacturers have long since abandoned this particular ship, it is still possible to buy an analogue synth (invariably modular) from specialist companies.

The seminal British synth company EMS is still producing two classic old-timers in the VCS3 and the Synthi A, and Digisound produce a large range of analogue synth modules from which custom instruments can be built. Components include VCOs, LFOs, VCFs etc., Dual Ring Modulators, Noise Generators, Keyboard Controllers (4/5 octaves), Reverberations units, and much more.

Roland only finally ran out of stock of their System 100M modules towards the end of the 1980s. These modules were powerful and well made. They can still be found second hand and are much sought-after.

FURTHER READING

Synthesizers For Musicians, by RA Penfold.
The Secrets Of Analog And Digital Synthesis, by Steve de Furia.
Synthesizer Basics, reprints of articles in Keyboard magazine (US).
The New Complete Synthesizer, by Dave Crombie.
Electronic Synthesizer Construction, by RA Penfold.

FURTHER INFORMATION

Obie Rack; MidiMini; Prophet V Rack; Oberheim OBM, Matrix 12, Matrix 1000, Xpander.
The Synthesizer Company, (Contact Details).

JL Cooper products; Evolution EVS1.
Sound Technology plc, (Contact Details).

EMS, (Contact Details).
Digisound, (Contact Details).
Philip Rees, (Contact Details).