I recently released a course on Lynda.com and LinkedIn Learning on how to use the Arturia Modular V software synth, which is modeled on the old Moog modular systems. In the movie below I show how to create a typical PWM (pulse width modulation) patch.
For those who don’t already know, PWM is the technique where you dynamically vary the width of the “square” waveform, changing it between a thinner, reedier-sounding pulse and something that more closely resembles a nice fat square. Changing the width of this pulse on the fly gives the aural impression of detuning or chorusing, as you get sort of a Doppler shift while the edge of the pulse is moving. This is an easy way to make a single oscillator sound like a pair of oscillators in unison but slightly detuned, and in general creates a more animated sound.
A few factors that make the typical PWM patch a little different in the Modular V software than you might expect on, say, your Eurorack modular include:
- Groups of three VCOs are controlled by an oscillator “driver” module which was common in the original modular Moogs. The pulse width for all three oscillators in that group are set by the driver, not by the VCO module.
- The VC LFO module has a PWM control of its own, which changes the shape of other LFO waveforms in addition to the square. Therefore, you might need to set the Manual control for the LFO’s PWM to one extreme or the other to actually get the shape represented by the graphic next to the output jack. (It’s the same with the main oscillators as well.)
- In Arturia Modular V, each input has a hidden inverting attenuator. To set the modulation depth coming into the PWM input on the oscillator driver, you click and drag just outside its virtual jack.
So with those notes in mind, here’s the technique; Arturia has made free demo version of the software available, if you want to follow along:
If that has whetted your appetite for the rest of the course, viewing it does require a Lynda.com or LinkedIn Learning subscription. If you’re not already a subscriber, sign up using the URL http://lynda.com/trial/chrismeyer and you will be able to view the entire course – as well as the nearly 300 other music & audio courses available – for up to 10 days before your credit card is charged. Cancel before then if you don’t find it useful; if you do, a single month only costs $25, going down to $20/month if you sign up for an entire year.