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3. Adding movement to our VCV Rack drone with LFOs and envelopes

1 Let’s take our basic drone patch even further. Though we like our slowly pulsing electronic klaxon, we’re going to crank the LFO’s Frequency up to nearly full. This provides a steadier tone, but one more complex than that of the VCO’s simple square wave. This is just standard, analogue-style FM. 2 Let’s add another LFO-1 module. Turn its Frequency nearly all the way down, and set the switch ( just to the left of the Freq knob) to the Bipolar position. Then, run a patch cable from this new LFO’s Triangle output over to the first LFO’s FM 1 input, and set the first LFO’s FM 1 knob to around 2 o’clock. 3 That’s a drone! Still, it’s cycling, so it might get too familiar too quickly. The answer is, obviously, another LFO! Route the Sin output of this third LFO to the VCF’s Freq input, and turn the VCF’s Freq CV to 1 o’clock. Push the filter’s Frequency down a bit and set its Resonance to around halfway. 4 This is getting quite interesting. Since all of our LFOs are cycling independently, the sound slowly shifts and changes over time. Let’s take a moment to tidy up our rack. We can add even more interest by layering in a second VCO. We’ll use the same sort: the VCO-1 module from the Fundamental category. 5 We’ll add another VCF and Delay, too. This time, we’ll route the new VCO’s Saw out into the VCF. The VCF’s LPF out will be sent to the new Delay’s In. We’ll disconnect our first Delay from the Audio module’s Input 2, replacing it with the second Delay, and set the new modules’ parameters to slightly different values from the first group. 6 We’ve now got separate signals being sent to each side of the stereo spectrum. Our original is coming from the left, while the new VCO/VCF/Delay are pumped through the right channel. We need to spice up that right channel. This time, we’re going to call upon the

Bogaudio Shaper module. 7 The Shaper module is an envelope generator inspired by the unusual looping trapezoidal envelope found on EMS’ VCS3 and Synthi A. Set the Cycle switch to the Loop position, patch its Env output to the new filter’s Freq CV input, and turn the VCF’s Freq CV knob to 2 o’clock. You need to push the Shaper’s Trigger button to get it started. 8 The Shaper is running a bit fast. Let’s set both its Attack and Decay knobs to 1 o’clock. They do as you would expect. The On knob acts as a ‘hold’ – set it to 9 o’clock. Finally, the Off knob determines the length of time between cycles. Set that to 1 o’clock, too. 9 Next, add another Shaper. Patch the first filter’s LPF to its In jack, and its Out to the first Delay module. Set it to Loop as well, and set Attack, On, Decay and Off to 2 o’clock. You’ll need to turn down the Signal level to avoid distortion. What a lovely drone we’ve got!