Step by step
1. Building a wavetable synth voice in VCV Rack
1 Let’s build a PPG-style wavetable synth voice. The idea behind wavetables is simple – some single-cycle waveforms are strung together end-toend to form a single digital audio file. The oscillator can instantly call upon any waveform in the ‘wavetable’ or modulate through them. We’ll start by going to File and creating a New empty rack.
2 We’ll need a MIDI controller to hear what we’re doing. Right-click in the empty rack, go to the Core category and choose MIDI-1 and Audio modules. Once they appear, select the correct interface for each. Next, instantiate an Audible Instruments Macro Oscillator. This is a multi-purpose digital module based on a design from Mutable Instruments.
3 Right-click into our Fundamental modules and grab a VCF, ADSR, and a VCA. We’ll also nab a Delay for sweetening. Connect the MIDI module’s CV Out to the Oscillator’s V/OCT In jack for pitch control. We’ll connect the MIDI module’s Gate Out to the ADSR’s Gate In. We’ll route the Oscillator’s Out to the VCF’s In. The VCF’s LPF goes to the top VCA In.
4 The VCA’s top Out goes to the Delay’s In, and the Delay’s Out to Inputs 1 and 2 on the Audio module. The ADSR’s Out goes to the VCA’s LIN jack. We can now play a sound. Crank up the VCF’s Freq for now. Scroll the Macro Osc’s Edit knob until the display says Wtbl. You should hear a decidedly digital bell-like timbre.
5 That’s only one wave in the wavetable. The Color knob is used to select the wave in the table. Give it a twirl, then set it fully anti-clockwise. What if we modulate that knob? Call up another ADSR and connect its In jack to the MIDI module’s Gate output. Patch the ADSR’s Out to the Color input on the Macro Oscillator.
6 Tweak the ADSR to push Color into action. Turn the Attack fully down and both Decay and Release to about 2 o’clock. Sustain will be at 10 o’clock. Now, if we play and hold a note, the wavetable sweeps through its waves for a classic PPG sound. Modulate the VCF with the same ADSR and tweak the patch a bit to taste.