Rob Papen's Favorite Synth Programming Techniques

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Rob Papen has become known for his line of virtual synths and effects, including Predator, Blue, and Blade. But he has a long history of programming synths and samplers, starting with the Waldorf MicroWave, the Ensoniq ASR-10, the E-mu Orbit 3 module, and the Access Virus. I’ve long admired his work and wanted to get some insights on his approach to crafting lead synth sounds. Hard at work on a new version of Blue, Rob took time to share some concepts.

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Detuned Saws Rule

The detuned lead is the most popular electronic dance music sound of the last 15 years. If you’d called up this type of sound on a disco or funk session 20 or 30 years ago, the producer would surely have yelled, “Tune that thing!” Overall the saw waveform rules for most such lead sounds. The cool thing is that you can produce this typical lead sound on any synth that has two oscillators.

Set both oscillators to a saw waveform and detune one -15 cents and the other +15 cents. You can even go as far as 20 cents in each direction. Use a 24dB lowpass filter, with the cutoff wide open. The attack time of the amp envelope should be between 1ms and 5ms, and always keep the envelope’s sustain level at maximum. Keep the amp envelope release rather short (5-90ms), but pay close attention to this setting, as it will really influence the rhythmic feel of your playing. It needs to be determined in context with the track, based on the song’s tempo.

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Rob sometimes likes to put a slight pitch glide on one of the oscillators. If your synth doesn’t have a dedicated pitch envelope or a freely assignable envelope to spare, you can use your filter envelope, since the filter cutoff is fully open. Assign it to the pitch of oscillator 2, with a modulation depth of 12 semitones (one octave). The pitch glide will start to act. Here, it’s essential to keep the envelope’s sustain level at zero, so you don’t transpose or detune the sound further. Keep the attack also at zero and use decay and release settings of 30 to 90ms. See Figure 1 (at left) for how this patch looks in Predator. Experiment with more modulation, increasing it to 24 semitones (two octaves). Also experiment with the “decay and release” setting, but keep both values equal.

Hip-Hop Brass Lead

Based on this lead, sound let’s make a brassy lead—the type often used in hip-hop. There’s already a nice pitch “attack” on the second oscillator, as was often used when simulating brass sounds on analog synthesizers. To get brassier still, reduce oscillator 1’s fine detuning to -5 cents, and oscillator 2 to around +5 cents.

We want to have a bit of filter movement inside this brass lead, so close the filter cutoff frequency to around 25 percent and open the filter envelope to 100 percent. This way we can use the envelope to shape some filter movement over time. Set the attack between 10 and 40ms, the decay between 300ms and 1.5 seconds, the sustain to 40 or 50 percent, and the release to 300ms (see Figure 2 at left). If your synth doesn’t show values like this, think of it as a relatively fast attack, a medium decay, a mid-level sustain, and a slight release with not too much “ring-out.”

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You now have a nice synth brass sound, but expression is important so let’s add more control. You could add vibrato via the modulation wheel, but another option is to use it to open the cutoff frequency of the filter. In Predator, the mod wheel is already available as a mod source inside the filter section. Other synthesizers may require it to be assigned within a modulation matrix.

Velocity is another factor that you can use for expression. Within dance music, Rob shies away from sounds that have too much dynamic range, as they can get lost in the mix. So, set the velocity’s modulation depth (or the volume’s sensitivity to velocity) to about 30 percent, instead of 100 percent as might be programmed on a piano sound.

Velocity control of filter cutoff is another great way to bring this type of sound to life.

Morph Into a Trumpet

With a few more tweaks, we can lead to another lead: a fusion-style trumpet sound for soloing (see Figure 3 at left). For building a single trumpet-like fusion lead sound, we only need one oscillator. We have two options: we can turn off oscillator 1 (leaving oscillator 2 with its little bit of pitch glide) or do the opposite. Better, we can toggle between these two and even make two versions. First, reduce any detuning of the oscillators to zero, as detuning only makes sense if more than one oscillator is playing. Now shut down oscillator 2, leaving the non-pitch-enveloped oscillator.

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To make the sound a bit more special, close the filter envelope amount to 65 percent and close the filter cutoff to between 10 and 20 percent. The sound is now far mellower. We’ve already assigned velocity and the mod wheel to the filter for expressiveness, but vibrato comes to mind with this lead sound. So we’ll assign aftertouch from the keyboard to the depth of the LFO that’s modulating pitch. If your synth has multiple LFOs, the first one is most often already assigned to produce vibrato. Don’t have aftertouch? Then assign control of the filter to a knob, slider, or ribbon, and use the mod wheel for vibrato. It sounds best if your synth has a delay parameter for the LFO, so that the vibrato comes in a few milliseconds after the attack.

Remember that for expressiveness, velocity, pitch-bend, the modulation wheel, and aftertouch all play essential roles to make the lead melody you play alive and dynamic. There’s also another thing you can use for expressive playing: your synth’s portamento or glide feature. Many synths have a mode where the glide only occurs between notes you play legato. So you can play clean detached notes, and then glide into a note by playing legato. Try this feature if your synth has the option.

To complete this sound, use a bit of reverb. Chorus is still possible, but it takes away the solo feel of this oscillator/trumpet sound. Don’t forget that we shut down oscillator 2. We can make a variation using oscillator 1 instead. Oscillator 2 has the slight pitch glide in its attack phase, which we created with a free envelope. Try tweaking the decay setting of the envelope as well as the envelope amount. Toggle between both the oscillators to hear the difference in sound. Interesting, isn’t it, how small changes can have a big effect on a sound?

Learn More From a Master

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If you’ve enjoyed this lesson, you may be interested to know that Rob has created a wonderful book and four-DVD set on synth programming, called The Secrets of Subtractive Synthesis: The 4 Element Synth. It’s available from Amazon and his website at