Fun with LFO's A quick modulation trick with two sawtooth LFO's. Fun with LFO's A quick modulation trick with two sawtooth LFO's.
by Zon Vern Pyles
Here's my favorite thing to do while using two sawtooth LFOs to modulate the pitch of an oscillator. If you experiment with this, you'll discover a "sweet spot" where the oscillator no longer has sweeping changes in pitch, but stepped changes in pitch that may convince some you're using a step-sequencer or a sample-and-hold -- when you may not have one at all. It's an endless source of patterns that may serve as an effect or as the core of a new tune. Plus, since these are repetitive patterns, you can make loops out of them for your sampler or loop-based music software.
You can produce this sound on any synth that allows the routing of two LFOs to an oscillator at the same time, and has one positive-going and one negative-going sawtooth LFO -- or two independent LFOs set to "saw," using positive modulation from one and negative from the other.
Example patch on a Clavia Nord Modular
While LFO1 is making the oscillator go "whoop whoop" (to hear the rising pitches,
click here), LFO2 makes it go "dooo dooo" (click here to hear the falling pitches). The magic happens when you mix them together and find the "sweet spot" -- a specific balance point where increasing or decreasing the mod depth of just one LFO results in stepped modulation (click). Try different LFO rates for each and then seek out the "sweet spot" again for a new pattern (click and click).
Modification by Wout Blommers