Logic & CV Processing

Modules for gate logic, CV comparison, and signal routing.

Logic Gates

LogicAnd

Outputs HIGH only when both inputs are HIGH.

let and_gate = patch.add("and", LogicAnd::new());

LogicOr

Outputs HIGH when either input is HIGH.

let or_gate = patch.add("or", LogicOr::new());

LogicXor

Outputs HIGH when exactly one input is HIGH.

let xor_gate = patch.add("xor", LogicXor::new());

LogicNot

Inverts the input.

let not_gate = patch.add("not", LogicNot::new());

Comparators

Comparator

Compares two voltages.

let cmp = patch.add("cmp", Comparator::new());

Inputs

Outputs

Use Cases

// Trigger envelope when LFO rises above threshold
patch.connect(lfo.out("sin"), cmp.in_("a"))?;
patch.connect(threshold.out("out"), cmp.in_("b"))?;
patch.connect(cmp.out("gt"), env.in_("gate"))?;

Min/Max

Min

Outputs the lower of two signals.

let min = patch.add("min", Min::new());

$$\text{out} = \min(a, b)$$

Max

Outputs the higher of two signals.

let max = patch.add("max", Max::new());

$$\text{out} = \max(a, b)$$

Use Case: Limiting

// Limit modulation depth
patch.connect(lfo.out("sin"), min.in_("a"))?;
patch.connect(limit.out("out"), min.in_("b"))?;  // Maximum value

Rectifiers

Rectifier

Converts bipolar signals to various forms.

let rect = patch.add("rect", Rectifier::new());

Outputs

Input:      ╱╲  ╱╲
           ╱  ╲╱  ╲
Full:      ╱╲╱╲╱╲╱╲

Half+:     ╱╲  ╱╲
           ──╲╱──╲╱

Half-:       ╲╱  ╲╱
           ──  ──

Audio Applications

• Octave doubling (full-wave rectify audio)
• Envelope following (rectify + lowpass)
• Distortion effects

Signal Routing

VcSwitch

Voltage-controlled signal router.

let switch = patch.add("switch", VcSwitch::new());

Inputs

Output

When select < 2.5V: output A When select >= 2.5V: output B

BernoulliGate

Probabilistic gate router.

let bernoulli = patch.add("bernoulli", BernoulliGate::new());

Inputs

Outputs

When trigger arrives:

• With probability P: fires A
• With probability 1-P: fires B

Use Case: Random Variations

// 70% chance of normal note, 30% chance of accent
patch.connect(clock.out("div_8"), bernoulli.in_("trigger"))?;
patch.connect(prob_cv.out("out"), bernoulli.in_("probability"))?;
patch.connect(bernoulli.out("a"), normal_env.in_("gate"))?;
patch.connect(bernoulli.out("b"), accent_env.in_("gate"))?;

Ring Modulator

Four-quadrant multiplier for metallic sounds.

let ring = patch.add("ring", RingModulator::new());

Inputs

Output

Mathematics

$$\text{out} = \text{carrier} \times \text{modulator}$$

Creates sum and difference frequencies: $$\cos(f_1 t) \cdot \cos(f_2 t) = \frac{1}{2}[\cos((f_1-f_2)t) + \cos((f_1+f_2)t)]$$

Sound Character

• Bell-like tones with related frequencies
• Metallic, robotic sounds with unrelated frequencies
• Classic AM radio sound