SuperDirt Voltage

A small set of SuperDirt synths and Tidal helpers to control modular synths. No MIDI required!

2023 updates:

• nDef synths
• Added saw, lfo triggered LFOs
• amp now controls the scale of gate, voltage, saw, ar, and lfo

---

Simple

The following synths, while easy to use, create a new CV instance each cycle. This can result in short gaps/breaks in between cycles. You can use Ndefs (below) above to remedy this.

Easy install, 1st step: Put voltage.scd into your SuperDirt/synths library.

2nd step: Evaluate voltage.tidal (or add to your bootTidal.hs config)

Pitch, with octave quantisation

-- change notes per octave on each cycle
d1 $ pitch "0 10 8 1" # octave "<12 31 8>" # x 1

pitch allows a pattern of note values. octave sets the amount of notes per octave. The pitch and scale values will be converted to 1v/octave. Both pitch and octave can be sequenced for some microtonal madness...

glide accepts a strengh (in semitones, relative to scale), a rate (in step length).

-- glide to pitch
d1 $ pitch "0 10 8 1" # scale "<12 31 8>" # x 1 # glide 12 0.5

Gate

-- sequence gate inputs
d2 $ gate "0 1 0 0 1 1 1" # x 2

gate will take a 0/1 pattern and return +5v signals for the 1 values. Use -1 if you need a -5v.

Voltage automation

-- create stepped automation
d3 $ volt "1 0.2 0.5 -0.2" # x 3

volt will allow you to sequence voltages however you like.

ADSR/AR

--- adsr
d4 $ adsr 0 0.2 1 0.2 # x 4

There is also just an ar helper too, which has a default D and S value.

-- create ar
d5 $ struct "t f t t" # ar 0 0.5 # x 5

-- patternise ar
d5 $ struct "t f t t" # ar (range 0.1 1 sine) "<0 0.4>" # x 5

In the above example, the attack time would grow for each triggered envelope over course of the cycle.

Sine LFO

This will create an sine waveform, the sine will restart with each cycle, which gives a neat synced/trigger effect for modulations.

d6 $ lfo 0.5 # x 6

Saw LFO

This will create a sawtooth waveform, the sawtooth will restart with each cycle, which gives a neat synced/trigger effect for modulations.

d6 $ saw 0.5 # x 6

Clock

-- clock cv output
d6 $ clock # x 6

clock will output a clock cv, which matches the bpm of your tidal project. You can slow / fast this as well.

Amp

Using the amp modifier in Tidal Cycles will scale the output of gate, voltage, saw, ar, and lfo. Awesome for creating more suble modulations.

d6 $ saw 0.5 # x 6 # amp 0.3

---

Expert

If you run into issues with gaps or clicks in the synth defs above, you can choose to use nDefs, which allow more consistent CV usage.

These need to be defined in your start up file.

Ndef

Defining Ndef synths provide a constant signal between cycles and instructions. You will need to define a separate Ndef for each instance you would like to use.

Pitch

 (
    SynthDef(\nPitch, {
      | out,
      channel = 0, 
      freq = 440, 
      portamento = 0 |
      var n = Lag.ar(log2(K2A.ar(freq)/440), portamento);
      var sig = LinLin.ar(n, -1, 9, 0, 1);
      OffsetOut.ar(channel, [sig]);
    }).add
  );

// define a unique name for each Ndef
Ndef(\cv_np).source = \nPitch;
Ndef(\cv_np).play(0);

// add to dirt library, give it a name that you will use in tidal
~dirt.soundLibrary.addSynth(\p, (play: {
    var latency = (~latency ? 0);
    var freq = ~freq;
    var channel = ~channel;
    var portamento = ~portamento;
    
    Ndef(\cv_np).wakeUp;

    // schedule the cycles, prevents delayed signals
    thisThread.clock.sched(latency - 0.025, {
        Ndef(\cv_np).set(\portamento, portamento);
        Ndef(\cv_np).set(\channel, channel);
        Ndef(\cv_np).set(\freq, freq);
    });
}));

After adding or evaluating the above in SuperCollider, you can use them like:

-- you can select pitch by number
d1 $ n "20" # s "p"

-- or by note name 
d1 $ n "c3" # s "p"

-- change channel output and/or portamento
d1 $ n "c3 f2" # s "p" # channel 1 # portamento 0.5

Gate

  (
    SynthDef(\nGate, {
      | out,
      channel = 0, 
      n, 
      portamento = 0 |
      var sig = LinLin.ar(n, -1, 9, 0, 1);
      OffsetOut.ar(channel, [sig]);
    }).add
  );

// define a unique name for each Ndef
Ndef(\cv_ng).source = \nGate;
Ndef(\cv_ng).play(0);

// add to dirt library, give it a name that you will use in tidal
~dirt.soundLibrary.addSynth(\g, (play: {
    var latency = (~latency ? 0);
    var n = ~n;
    var channel = ~channel;
    var portamento = ~portamento;
    
    Ndef(\cv_ng).wakeUp;

    // schedule the cycles, prevents delayed signals
    thisThread.clock.sched(latency - 0.025, {
        Ndef(\cv_ng).set(\portamento, portamento);
        Ndef(\cv_ng).set(\channel, channel);
        Ndef(\cv_ng).set(\n, n);
    });
}));

---

Fine print

These require a DC-coupled sound card.

Add the voltage.scd synths to your active SuperDirt synth definitions.

Evaluate the voltage.tidal definitions after starting Tidal. These can also be added to your Tidal startup file.

In the above examples, x maps to a channel on your audio card. If you have an 8 output audio card, the x will likely be 0-7. If you are using an aggregate device, please refer to your Audio settings.

---

Feedback and/or additions?

If you are actually using this, please join the community here and let me know: https://club.tidalcycles.org/t/using-tidal-to-control-modular-synths-with-cv/863