John Holdun

The ideal synthesizer control surface

It’s been over a year since I started earnestly trying to write and perform electronic music. I’m really enjoying it! There have been many ups and downs as I learn what is fun and exciting and successful for me, and this lil article is not an introduction. It’s just one of the first things I’m really writing down1.

I’ve been playing live for an hour every Sunday night, and starting a couple jams ago I added some new synth voices to my ~DAWless~ setup that are just Pure Data patches running on a headless Raspberry Pi that’s tucked under the desk. It’s a revelation and makes me never want to even think about buying another digital synth. There are suddenly so many possibilities!

The question I’m trying to answer now is how best to control and shape the sounds of these voices. I have two points of comparison in my current setup: The Arturia Minibrute 2S, which is basically one-knob-per-function; and the Korg NTS-1, which has almost as many parameters but hides them all under like twelve modes that each expose three parameters at a time. I prefer the former.

I love MIDI controllers and I have a bunch of them that are going unused right now. Available desk space notwithsatnding, I want to introduce one or two to add more control. I just need to decide what I actually want to control.

Based on a lot of research—comparing and contrasting the interfaces of popular commercial synths—here are 24 controls that I think basically give you everything you need hands-on subtractive synthesis.

  1. Mixer for square/saw wave (crossfader-style)
  2. Glide: 0-50% for normal glide, 50%-100% for legato glide (inverted); at 0% the voice becomes polyphonic
  3. VCF Cutoff
  4. VCF Resonance
  5. VCF key track
  6. VCF Attack
  7. VCF Decay/Release
  8. VCF Sustain
  9. EG → Cutoff
  10. Velocity → Cutoff
  11. VCA Attack
  12. VCA Decay/Release
  13. VCA Sustain
  14. EG → VCA
  15. Velocity → VCA
  16. LFO Rate: 0-50% is free running; 50%-100% is a clock divider
  17. LFO → Pitch
  18. LFO → Cutoff
  19. LFO → VCA
  20. Chorus Time
  21. Chorus Level
  22. Unison/detune/hard sync (I haven’t decided how this knob would actually work yet)
  23. Sub-oscillator level: A sine wave one octave below the pitch input
  24. Volume

24 is a nice number because it’s a multiple of 8, and most MIDI controllers offer controls in multiples of 8. There are 24 knobs on the top half of the Novation Launch Control XL, which seems like a great choice for this.

Not all of these 24 controls are necessary for a synthesizer2. I think having all of them is good for flexibility on a lead, while a pad or bass voice could probably ditch a few, or share one envelope between VCA and VCF, or otherwise creatively reduce the number of controls.

I think that’s the beauty of soft synths and MIDI controllers. As the performer, you get to decide what’s important to tweak. Although that’s also a curse, because you end up writing things like this.

  1. I guess there’s also the stuff I wrote about building a sequencer, which is basically a separate journey of its own. Right now all my sequencing happens in a Digitakt, and it makes me very happy, but also I could be doing so much more! 

  2. There are also some specific omissions. This list includes Chorus but no Delay or Reverb, because for me they’d be redundant over the effects sends in my mixer. Similarly, there’s no Pan control, although I imagine the Chorus would be stereo, so maybe I do need Pan, or I need to move Chorus to another send channel. Also, where’s PWM, and LFO shape, and uhhh noise? Time to rewrite this.