Synth Up Your Sound part 3: Wobble, Woosh and Chop

 Frank lays down some huge filter modulation @ 2:11

Ok, so a synth’s oscillators make the basic sounds, but much like a note on the guitar, it’s more interesting to make that sound move!  We’re talking modulation.  On a guitar you can physically shake you hand and create vibrato.  On a synth we gotta go to the LFO or Low Frequency Oscilator.  These create slow and low waves that you don’t exactly here but effect the things that you can.  LFO’s are in many of the pedals that you may already own(chorus, Flanger) but a synth aproaches them in a different way.  You can actually choose what part of your sound will be controlled by the wave that the LFO throws out.  You can also select the kind of wave to warp it.

Let’s take a look at the three most common places to apply the LFO, what it does and how to mock it with pedals:

Earthquake Devices' Sea Machine takes Chorus/Vibrato to 20,000 leagues down.

EHX Stereo Pulsar will help you dial in the perfect tractor beam or mothership landing.

Oscillators
In a synth the VCO’s determine the pitch.  If you put an LFO wave on it, it wobbles above and below the note played.  This is vibrato. Obviously you could just use a vibrato pedal.  Try to choose one with more parameters than two to dial in a Moogier sound.  A chorus pedal will get you close although it will add a bit too much of the normal signal to make it “Synthish”.  

The VCA(Voltage Controlled Amp)
This controls the sound over a period of time affecting the attack, decay, sustain and release of a note.  Since it amplifies, when an LFO is applied the volumes are effected creating everything from smooth pulses to agressive chops.  The pedal equivelent= Tremolo.  Try a tremolo with varied wave forms to get closer to the sqare and triangle waves common in synth mods.





Filters
Depending on the type, a filter blocks certain sections of the frequency from getting through to alter the sound.  There are different parameters that you can control on a filter(Cutoff, amount, resonance).  The cutoff is a very common parameter to adjust and results in the classic sweeping woosh that synths are known for.  Wahs and Auto wahs(Envelope Filters) have been common for years but recently filter modulations have become popular again but fused with modern advancements that can create sequenced and random effects.  Check out the Moog MURF.  Huge fun.

Turn Some knobs!