Oscillator

Module ID: osc.sine Category: Sources Header Color: Blue

The Oscillator module

Description

The Oscillator is the primary sound source in Modular Synth. It generates periodic waveforms at audio frequencies, producing the raw tones that can be shaped by filters, envelopes, and effects.

This is a VCO (Voltage Controlled Oscillator), meaning its frequency can be controlled by external signals, enabling keyboard tracking and vibrato effects.

Inputs

Outputs

Parameters

Waveforms

Sine

Pure tone with no harmonics. Useful for:

• Sub-bass
• FM synthesis carriers
• Pure, flute-like tones
• Smooth modulation sources

Sawtooth (Saw)

Contains all harmonics with decreasing amplitude. Useful for:

• Classic synth leads and basses
• Strings and brass sounds
• Rich source material for filtering

Square

Contains odd harmonics only. Useful for:

• Hollow, woody tones
• Clarinet-like sounds
• PWM for chorus-like effects

Triangle

Contains odd harmonics with rapid rolloff. Useful for:

• Softer than square, brighter than sine
• Flute and soft lead sounds
• Smooth modulation

Usage Tips

Basic Pitch Control

Connect a keyboard or MIDI module's V/Oct output to control pitch:

[Keyboard] ──V/Oct──> [Oscillator]

The V/Oct standard means:

• 0.0 = Base frequency (set by Frequency knob)
• 1.0 = One octave up
• -1.0 = One octave down
• 0.083 = One semitone up (1/12 of an octave)

Vibrato with LFO

Connect an LFO to the FM input for vibrato:

[LFO] ──> [Oscillator FM]

• Use low FM Amount (0.1-0.2) for subtle vibrato
• Higher amounts create more dramatic pitch wobble
• LFO rate of 5-7 Hz is typical for vibrato

FM Synthesis

Connect another oscillator to FM input for FM synthesis:

[Oscillator 2] ──> [Oscillator 1 FM]

• Sine waves work best for clean FM tones
• Integer frequency ratios (2:1, 3:1) create harmonic sounds
• Non-integer ratios create inharmonic, bell-like tones
• FM Amount controls brightness/complexity

Pulse Width Modulation

For square wave, modulate pulse width with an LFO:

[LFO] ──> [Oscillator PWM]

• Creates a chorus-like, animated effect
• Extreme PW values (near 0.1 or 0.9) create thin, nasal tones
• Slow LFO rates create subtle movement
• Fast rates create more dramatic timbral changes

Hard Sync

Connect a sync signal to reset the waveform cycle:

[Oscillator 2 Out] ──> [Oscillator 1 Sync]

Hard sync creates complex, aggressive tones:

• Oscillator 1 (synced) resets when Oscillator 2 completes a cycle
• Sweep Oscillator 1's frequency for the classic sync sweep sound
• Works best when synced osc is higher frequency than master

Detuning for Thickness

Use two oscillators slightly detuned for a thicker sound:

[Osc 1 (Detune: 0)] ──┐
                      ├──> [Mixer] ──> [Filter]
[Osc 2 (Detune: +7)] ─┘

• Small detune values (5-15 cents) create subtle chorusing
• Larger values (20-50 cents) create a "supersaw" effect

Connection Examples

Typical Synthesis Chain

[Keyboard] ──V/Oct──> [Oscillator] ──> [Filter] ──> [VCA] ──> [Output]

FM Bell Patch

[Oscillator 1] ──FM──> [Oscillator 2] ──> [VCA] ──> [Output]
     (Modulator)           (Carrier)

Dual Oscillator with PWM

[LFO] ──> [Osc 1 PWM]
          [Osc 1] ──┐
                    ├──> [Mixer] ──> [Filter]
          [Osc 2] ──┘

Related Modules

• LFO - For vibrato and PWM modulation
• SVF Filter - Shape the oscillator's harmonics
• VCA - Control oscillator volume
• ADSR Envelope - Shape the sound over time