Curtis Schwartz outlines two of his home grown patches for Yamaha's DX7

There are a new breed of synthesists emerging in the mid-eighties. Synthesists whose minds are capable of grasping the fundamentals of such things as nuclear physics, organic chemistry, SDP manifestos and suchlike. This is due to the increase in complexity (and versatility) of the synthesiser. However, not all keyboard players have risen to the challenge, many are content to use the preset voices in a synth which, although they are usually excellent, do not give the player his own unique sound. Thus, with a machine such as Yamaha's DX7, the permutations of the 128 parameters per note, although extremely versatile, can prove overwhelming to your average musician.

Dual method

There are two methods by which you can program the DX — the start-from-scratch method, and the just-by-chance method. With the latter, one starts with a standard patch and changes the algorithms and frequencies of operators till one comes across a sound which is agreeable to you. This can result in some very unusual and exciting sounds. The start-from-scratch method is more calculated and longwinded, yet I find it to be infinitely more rewarding. To begin with, you must think of the sound and how it is made. In the Piano patch printed below, operator number five is giving a 'thump' which has the effect of giving the sound more realism as well as providing the player with the psychological sensation of hitting more than a set of plastic keys. Such elements in the sound should be thought out before choosing the algorithm with which you are going to work. For complex waveforms, an algorithm with many modulators and fewer carriers is preferable to one with several carriers. Several carriers are useful for sounds that are made up of several elements or some detuning in the sound.

Therefore, with the Piano patch we are using an algorithm with two carriers — the fourth operator providing the depth and weight to the sound, and the first operator giving a little more of a piano's harmonic characteristics (1). The two are detuned from each other to add even more richness to the tone, and yet more movement is achieved by giving operator four (a carrier) a fixed frequency of one Hertz. This acts as a LFO for the equivalent of Pulse Width Modulation.

By careful use of keyboard scaling, the realism is retained throughout the DX's five octave range, and if you have a listen to the tape I think you'll agree that it sounds great.

The other patch we have printed out is a 'tough' acoustic guitar voice. This again uses an algorithm with only two carriers, the first of which (1) is providing the initial attack as well as the depth to the sound, and the other carrier (3) gives the fundamental sound or waveshape of an acoustic guitar. The touch-sensitivity is quite strong, and some aftertouch vibrato, although not strictly accurate in simulating an acoustic guitar, does suit the sound quite well nevertheless. Again we have a fixed frequency operator being used, this time providing the voice with a slight metallic pluck at the beginning of each new note.

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