by Todd Albertson
This month we journey back in time. Further and further we go, before the time of the prophets (Prophet V, Prophet X, etc.), before the time of the ancient gods (Jupiter, Super Jupiter, and the other early Roland synths), before even the time of the Great Wizard (Robert Moog), to the time of the DINOSAURS. This was the age of the Great Transition. The old Tube kings were losing ground rapidly to the mighty Transistors, electrons flowed more often than not, and men began to understand that the world would forever be a smaller place.
In the 1950's, researchers experimenting with simple, common, electrical circuits devised entirely new ways of connecting the outputs and inputs of these circuits one to another. This was accomplished using the common "patch" cords still in use today. The circuits were connected in ways that usually produced ugly sounds, but SOMETIMES, very interesting and MUSICAL sounds. Each sound was the result of "patching" one module to others, hence the sounds created were dubbed "patches" ("I'm dependin' on ya, son"). Sorry about that. Anyway, the name stuck and sounds created using synthesizers are still referred to as "patches."
The modern synthesizer is really the same system used by these ingenious pioneers, except that the independent modules are all included in one neat little package, utilizing super clean internal connections instead of patch cords. This is a tremendous benefit but we did lose something in the bargain. Since all the modules are already connected internally, we have no choice but to use the modules supplied by the manufacturer. We no longer have the freedom to mix and match sound modules, substituting one say, filter, for another. In practical application most musicians struggling to get a particular sound or feeling are simply not aware of the fact that if they only had the ability to swap a certain module with another of slightly different characteristics, the sought sound might be easily achieved. It is ABSOLUTELY CRUCIAL that aspiring synth programmers retain the perception of independent modules, even though they are all housed in a single unit. If the operator perceives the "separateness" of these modules and endeavors to understand the individual characteristics of each, there is a good chance that the later complex interactions of these components will also be understood.
So let's look at the names and functions of each of these components, one by one starting with this month's main event, Source Modules:
The Source Module, or OSCILLATOR might be called: VCO (voltage controlled oscillator), DCO (digitally controlled oscillator), Operator (these Yamaha modules are in some ways very unique), Partial (Linear Algorithmic synths such as Roland's D 50, and Kawaii's awesome K 1), Sampled Waveform (Some Korgs, Ensoniqs and others), or maybe even some other name I have yet to see. These modules are the "source" modules of the instrument's sound. The other modules in an instrument will usually serve to modify, add to, subtract from, or otherwise alter the sound generated by these "source" modules. In its simplest form, the oscillator creates a pure sine wave which can then be pitched upwards or downwards from the keyboard. In the case of the old VCOs (voltage controlled oscillators), each key had an output voltage relative to its pitch. This voltage was sent to the VCO which reacted appropriately. This system is considered by manufacturers to be completely antiquated, but many musicians disagree. You see, voltage is not a completely predictable and stable thing. In most circuits, it fluctuates slightly with temperature, humidity, and simply at random. If the voltage is not absolutely stable, what do you suppose happens to the pitch of the oscillator (and therefore the whole instrument)? You guessed it, the pitch is not absolutely stable either! These tiny fluctuations often gave the early synths a "human" quality unattainable by most newer systems. Ah well, that's progress.
Next we come to the far more stable DCO. Digitally Controlled Oscillators vary pitch according to number. Each key on the keyboard generates and sends this number to the oscillator which then reacts just as its predecessor did, by moving the pitch upwards and downwards as "called" by the keyboard. This system has proved to be an excellent one as oscillators using numeric control are still able to achieve a "warmth" that comes from the non-digital nature of the rest of their circuitry. In other words, even DCOs are still slightly unstable, electronically. The additional benefit, and raison d'etre of this system is that it permits MIDI control. Roland's outstanding low cost Juno 106 was, and is still an extremely popular synth (Right, Bumper?!) utilizing this source system. Consider purchasing this fine used instrument for excellent sweepers.
Enter Yamaha. The DX 7 synthesizer became the world standard overnight because of its ability to produce "struck" and "plucked" sounds. This ability comes from Yamaha's unique "Operators" and the substructure surrounding them. These instruments have the very serious drawback of a "cold" sound. That is to say, their systems are so stable as to become unnatural, or unmusical at times. Musicians and producers quickly learned to "layer" several DX 7s slightly out of tune with each other (detuned) to achieve the warmth required. Another trick was to process these instruments through chorus units. They were noisy, heavy and contained only limited patch memory, but they had the most wonderful feeling in the keys themselves, and that special quality of "struck" sounds. An operator tutorial is far, far beyond the scope of this article (in fact, it would require more pages than the entire magazine), but you may wish to know that Operators are not only source modules, they act as modifying modules also. It is this unique characteristic that, more than any other, created the now famous "DX sound." Yamaha wisely chose to include tutorials with all DX series synths, beginning with its release of the DX 9 (a DX 7, stripped of touch sensitivity, and some operators). The tutorial supplied is excellent and readable so there is no reason to fear purchasing one of these as long as the manuals are included. Be forewarned that each DX patch can take several hours to produce as the possible combinations of operators and modifiers are ENDLESS! Also remember that these are not particularly full and warm sounding instruments without many hours of work and assistance from outboard gear.
In an effort to stay afloat after Yamaha dropped their digital bomb on the music world, manufacturers began to look for ways of achieving that "struck" sound. Yamaha's patents were so well written that it was completely hopeless to use similar approaches. A suitable alternative was found in "Sampled Waveforms." Sampled Waveforms are basically digital (and therefore perfect) recordings of other sounds which are then stored in ROM (read only memory) in the synth. How WONDERFUL! A new world unfolded with this innovation. Essentially what we have here is any sound the manufacturer wishes to place in the instrument, waiting for us to modify it with simple, easy to use, conventional modifier modules common to most synths. Unlike Yamaha's products, basic concepts can be applied from one manufacturer to another. Also, manufacturers began to develop distinct styles in their choices of samples to save in their respective synths. The ESQ 1, and its big brother, SQ 80, are absolutely smashing examples of this approach. They are both affordable, easy to use, and come with the best manuals written in the entire industry. The one flaw is that perfect, digital, sometimes unmusical, stability of the source module supplying the Sampled Waveform. Ensoniq saw the flaw, took it seriously, and supplied so many, and so varied an assortment of modifiers, that nearly anyone can program it well. Add to this the fact that conventional names are retained (they refer to the source units as oscillators) and these are among THE BEST buys available today. A less expensive, (and in my opinion underrated) choice is the DW 8000 by Korg.
Lastly, in our tour of source modules, let us briefly examine the Linear Algorithm approach developed by Roland. Roland's D 50 in many ways replaced the DX 7 as the industry standard. The sound most familiar might be the "chiff flute" in the theme from "Thirtysomething." Although I have no way of knowing whether or not a D 50 was actually used in that music, it is the "breathy" voices, flutes, and other instruments which characterize this instrument. Like the DX 7, it too has the ability to make struck sounds. At long last however, here was the first natural, musical sounding digital instrument. The D 50's source modules are referred to as "partials" and the name offers a clue about their purpose. Partials are meant to be used in conjunction with each other and are best when "stacked" into "multi" voices or patches. These partials are digital in nature, but constructed in such a way that using them with each other in patches gives that full warm sound so sought after by musicians and producers alike. Problems with the D 50? ...Cost. Buy one of these and you can forget about the down payment on that new car! Recently however, Kawaii (did I say Kawaii?) surprised everyone by offering a D 50 clone that outperforms its predecessor for a miserly price, less than half of the D 50's. I'm waiting to see how Roland retaliates (lower prices, or an even more capable synth).
Well, that's the big source module tour. Next month we'll breeze through the modifiers, and after that, we can begin to seriously look at what MIDI is and how it interacts with all this. Until then: Live long, and prosper.
♦