Step by step
3. Exploring FM synthesis with Arturia’s DX7 V
1 The DX7 V is a 6-op FM synth, meaning that we have six operators – or oscillators – to deal with. Traditionally, these operators need only to produce a sine wave: interesting timbres are created by modulating the frequencies of some of these sine waves with others. Let’s fire up the synth and start off by loading the Default template.
4 Here, we see all of our operators arranged in a column on the left. We can select each one, revealing its settings in the process. Operator 1 is selected and, in fact, is the only one with the Level turned up. Let’s select OP2 and increase its level, noting the effect on both the sound and the waveform display in the lower-right corner.
2 In the centre, we see the currently selected algorithm. This shows which operators are routed to which, and the ones that are are routed straight to the outputs. In this case, operators 1 and 3 are the audio operators, while operator 2 is modulating operator 1. Operator 3 is modulated by 4, which itself is modulated by 5 and so on. Operator 6 is modulating itself and op 5.
5 This has a big effect on the sound, and the waveform’s shape in the display. Try increasing operator 2’s Freq amount to 3. This is much more dramatic. Notice there’s an envelope display in the lower middle of the panel – let’s tweak that envelope a bit. We’ve reduced the Sustain node dramatically and dragged it to the left to create a short decay.
3 With all of these operators in play, we nevertheless hear only a simple sine wave. Only operator 1 is illuminated in the display, indicating an active signal. Let’s dig deeper by either doubleclicking the operator in the algorithm, or clicking the double arrows in the upper right. Now we can see inside our patch.
6 This has a big effect on the sound, providing an exciting attack and decay segment that settles to a muted sustain segment. Knowing how envelopes and other mod sources are used to shape our modulation operators unlocks the power of FM synthesis. Now bring in other operators and tweak their envelopes, frequencies and ratios to develop the sound further.