Double, Detune, and Drift
This is the most basic thing you can do with a synth to
fatten things up. It’s been covered here before, so I’ll touch on the
basics and offer one interesting twist. Detuning is nothing more than
doubling a signal (say, a sawtooth wave oscillator) with one of the two
signals tuned slightly up and other tuned slightly down. It’s the
synthesizer version of a chorus effect. Usually the amount of pitch
offset is somewhere between two and ten cents up or down.
A less common trick is to emulate the slight pitch drift
that occurs on classic analog synths like the Minimoog. Some synths have
a dedicated parameter for this tuning imperfection—called drift, analog
feel, detune, or something similar. The way Weiser likes to accomplish
this is to use an LFO to slowly modulate the pitch ever so slightly on one
oscillator of a detuned pair. Anything that introduces irregularity is
going to be more pleasing to the human ear than sounds that are static.
Why do this instead of using the general detuning settings? The sound
gets a bit thin if the oscillator veers back to a perfect unison, so you
should keep some tuning difference between the oscillators at all
Set Filters on Phase!
Another doubling trick is to use an allpass filter to
create a phaser effect. This lets you build a simple phaser signal path
using a filter rather than running a sound through an onboard effect.
Dave likes to do this because it adds some simple motion without
sounding as deeply “effected” as using the DSP effect. And some effects
don’t allow the modulation we’re looking for here.
A signal going through an allpass filter retains its
amplitude level, but certain frequencies will be placed out of phase. By
combining the all-passed signal with the original, unaffected signal,
the out-of-phase frequencies will cancel out, creating a dip or notch
in the sound. Using an LFO to modulate the allpass filter’s frequency,
you can cause this notch to sweep up and down over time: the classic
phase shift effect. The key here is to have a separate filter for each
of the oscillators, so only one is running through the allpass filter.
Some synths offer a filter topology that provides parallel filter
routing so each oscillator can be routed to an individual filter; others
user smaller building blocks of an oscillator, filter and amp that can
be combined. Roland calls these Tones, which are combined to make up a
Patch; Yamaha calls these Elements, which are combined to make up a
Voice. Most samplers (and Kurzweil synths) call these Layers, which are
combined to make up a Program. However your synth does it, you want two
oscillators programmed basically the same, slightly detuned, with one
running through a standard lowpass filter, and the other going into the
allpass filter (Kurzweil PC3 series workstations, Native Instruments
Absynth and Massive, and Spectrasonics Omnisphere all offer one.) Some
synths provide a discreet notch filter (Absynth, Omnisphere, and Applied
Acoustics Ultra Analog VA-2) in which case you’ll only need one layer.
You can take it one step further by assigning the LFO rate
control to a physical controller such as a wheel, slider, or knob.
Being able to speed up the LFO adds an unexpected “blast off to outer
space” effect that can be a welcome change of pace from the standard
synth-lead vibrato. Of course you can do this as a secondary control if
you still want to use your “normal” vibrato, or add a little bit of this
phaser LFO speed control to your modulation wheel—along with the vibrato—for a unique, spacey sound.
Still can’t get there? Some synths can’t process each
oscillator individually. The classic Minimoog design is but one example
where all the oscillators are fed into the same filter. What can you do?
Create two copies of the same Program and layer them using a Multi or
Combi mode, or use two tracks in your DAW set to the same MIDI channel.
One can have the lowpass filter and be detuned flat, the other can have
the allpass or notch filter and be detuned slightly sharp. This
“modular” approach to building a sound from multiple synth programs may
be unfamiliar and a bit unwieldy, but it will yield some amazing
Pedal to the Metal
| || |
| Fig. 1. The Ibanez TS-9 Tube Screamer is perfect for adding some serious distortion to your leads.||Fig. 2. Radial’s Tonebone Plexitube is tube-driven and offers more distortion and tonal color options. |
Even though most of today’s hardware synths have onboard
effects, Dave still likes to use guitar-oriented stomp boxes when
playing live. There’s something visceral about being able to toggle a
box dedicated to doing one thing well. Sometimes, a hardware stompbox
simply has the right sound, especially in the area of overdrive
and distortion. Many guitar, amp, and pedal companies live for getting
that sound right, after all.
For distortion try the Ibanez Tube Screamer pedal (see Figure 1 above).
It kills and costs relatively little. It’s a great way to almost
instantly get a passable lead guitar sound out of a monophonic synth
patch (of course there are plenty of other distortion pedals out there
that will do the trick). Add wah and analog delay pedals for additional
lo-fi gratification. Want some more unique effects? Explore the world of
pedals made by Electro-Harmonix, Pigtronix, Radial Engineering (Figure 2), and the Moogerfoogers.
This trick might be the most fun of the bunch. Set up an
arpeggiator with a tempo matching the song you’re playing. Set the note
timing to sixteenth- or 32nd-notes and the range to two octaves, and let
the sonic mayhem ensue. You won’t need to play fast—hitting eighth- or
even quarter-notes will make for an insane solo. Bring it in at a choice
place in your solo, turning on the arpeggiator for some “you know who”
fretboard hammering solo fun.
Most arpeggiators generate notes that are always above the
trigger notes you actually play. Some arpeggiators have settings that
allow you to choose which direction the pattern will travel from the
trigger notes, either above, below, or both. Yamaha, Roland, and others
offer such a choice, as do most Kurzweil workstations. Other than those,
we’ve found the above-and-below option in Applied Acoustics Ultra
Analog VA-2 and the M-Audio Venom synth.
Kurzweil calls these choices “unipolar” (one direction),
“bipolar” (both up and down are possible) and “random”
(self-explanatory) with the range being set with both positive and
negative numbers. I like to use bipolar, meaning that the pitch will
shift both up and down from the held note, with a range of plus/minus
two octaves. When you hold a single note, you’ll hear the initial pitch
followed by notes one octave up, two octaves up, one octave up, back to
the initial pitch, then one octave down, two octaves down, et cetera, in
machine-gun succession. See Figure 3
above for an example of this, and listen to the online audio to hear it in action.