Just Until The Swelling Goes Down

In the last couple of years the venerable Prophet-5 has been recreated virtually in a number of guises, notably with Native Instruments Pro-53 and Arturia Prophet-V, the latter of which combines an emulation of the original Prophet with Sequential’s later Prophet VS digital/analog hybrid synth. This month I’d like to share a pretty cool Prophet patch from my personal stash. It’s featured on my track “Transactions,” on my new CD, which I would, uh, never blatantly promote here. (Hint: www.celebusite.com. . . must . . . not . . . self-promote . . . .)

It’s kind of a spooky pad that slowly swells in from nothing and then ends rather abruptly. As a result, it sounds a little backwards, since the envelopes are set in the opposite way of most piano or guitar-type patches. I also did some trickery to make it very wide and stereo-ized, which is a technique you can apply to other sounds. Instead of blathering on forever about how it sounds, you might want to check out the samples to the right or at www.celebutantemusic.com/keybmag. I created this patch using Native Instruments Pro-53. You don’t really a need a Prophet (real or virtual) to do it; just about any two-oscillator polysynth with pulse-width modulation will do. Use whatever you’ve got, friends.

Let’s start with two oscillators at equal volume and set the octaves to a middle range with both in the same register. Use the fine pitch knob to detune oscillator B by a fair amount; about 30 cents. It should sound kind of seasick, but not so out of tune that it’s unplayable. Select the square waveform for both oscillators as well. On some synths this will be called PWM; you want the one with variable pulse-width (some synths have a fixed square wave). Now we want to route the low-frequency oscillator (LFO) to modulate the pulse width of the square wave. That’s a scary sounding sentence, but all it means is that instead of turning the pulse width knob back and forth for timbral animation, we’re going to have our friend the LFO do it automatically for us. Moving to the LFO section, select a triangle waveform, and set the speed to about 60Hz. You can match it up to the audio examples if your synth doesn’t show the exact speed. If you’re using Pro-53 in Logic, you can select the Editor page in the plug window to accurately display the knob increment values. Now we want to route the LFO to control pulse width. On a Prophet, you’ll go to the Wheel-Mod section, select PW A and PW B, and then crank the mod wheel up about two-thirds (I’m referring to the virtual mod wheel next to the keyboard in the plug-in interface, not the actual mod wheel on your MIDI controller).

Moving over to the filter, we want a lowpass with the cutoff frequency about 40% open or less; we’re going to use the filter envelope to do most of our cutoff control. Resonance should be at about 20% just to focus the sound a bit. You’ll want to experiment with the filter envelope times depending on the tempo of the song, but for my 139 bpm tune, I had a relatively long attack and decay, sustain almost full up, and zero release time. The really important thing is to crank up the envelope amount knob so that the envelope takes the sound from semi-dull to wide open. Keyboard tracking can be at 100%. The amplitude envelope will look similar to the filter, but you’ll want to speed up the attack; most of our “swell” effect is coming from the filter sweep, not an actual volume change.

The PWM and wide oscillator detune should have things sounding pretty fat, but we’re still in mono. For a nice stereo-ization, I used an aux send to add a 10ms delay. I panned the Pro-53 patch a little to the right, and the delay hard right. Now things are big. Just don’t let the swelling get out of hand.