Phase Modulator
Dual Mode PM / Native & AUv3
1,99 €
Phase modulation that bends a carrier's running phase with a second source. Drive it with two internal variable wave oscillators, or feed your track in as the modulator.
PHASE MODULATOR
Phase modulation perturbs the running phase of a carrier oscillator with a modulating signal. Sweeping the phase back and forth generates a series of sidebands above and below the carrier, spaced by the modulator frequency, whose number and strength grow with the Index. This is the same technique behind classic FM synthesis: small index values add a little harmonic shimmer; large values produce dense, clangorous, often inharmonic spectra. The carrier you hear is always an internal oscillator. What changes between modes is where its phase modulation comes from.
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CONTROLS:
CAR FREQ
Frequency of the carrier oscillator, 20 Hz to 20 kHz. This is the audible tone in both modes.
CAR AMP
Level of the carrier oscillator before the Output gain.
MOD FREQ
Frequency of the internal modulator oscillator, 20 Hz to 20 kHz. Active in Osc + Osc only. The carrier-to-modulator frequency ratio sets the harmonic character: integer ratios give harmonic, pitched tones; non-integer ratios give bells and metallic, inharmonic results. In Input + Osc the modulator comes from your audio instead, so this control is inactive.
MOD AMP
Level of the modulation source before it reaches the phase. Together with Index it sets how far the carrier phase is pushed; think of it as a trim ahead of the Index multiplier.
INDEX
Modulation index, 0 to 10. The headline control: peak phase deviation in radians equals Index times the modulation signal. At 0 the carrier passes clean; raising it brings in progressively more sidebands and brightness.
OUTPUT
Makeup gain after the effect, -24 dB to +36 dB. No limiter follows this stage, so watch your meters when boosting.
WAVEFORM
Carrier oscillator shape: Sine, Saw, Triangle, or Square. Sine is the classic FM voice. The richer shapes already contain harmonics, so phase modulating them produces denser spectra and reacts more aggressively to Index.
MOD WAVE
Modulator oscillator shape (Osc + Osc mode only): Sine, Saw, Triangle, or Square. Changes the harmonic character of the modulation itself. In Input + Osc mode the modulation comes from your audio, so this picker is inactive.
FOLLOW
Input + Osc only. With Follow On (the default) the carrier tracks the amplitude of your incoming audio: it speaks only while signal is present and falls silent when the input does, so the plugin behaves like an effect rather than a constant tone. With Follow Off the carrier runs continuously at its set level regardless of input, which suits drones and sustained textures. In Osc + Osc there is no input to follow, so this control is inactive.
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MODES:
OSC + OSC
Both carrier and modulator are internal oscillators, set by Car Freq and Mod Freq. Classic two-operator FM with no input required, good for bells, electric pianos, and metallic drones.
INPUT + OSC
Your track's audio becomes the modulation source, perturbing the phase of the internal carrier oscillator. Note that what you hear is the carrier shaped by your audio, not the audio itself passed through; the input controls the timbre rather than being processed in place. Mod Freq does not apply in this mode. This is the default mode.
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A NOTE ON ALIASING
Phase modulation can scatter energy well above Nyquist, so the effect runs internally at four times the host sample rate and filters on the way back down. At extreme Index settings with the saw or square carrier some residual aliasing can remain; lower the Index or the carrier frequency if you hear gritty, detuned overtones.
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The developer, Daniel McKemie, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
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The developer does not collect any data from this app.
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Information
- Size
- 8 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Age Rating
4+
- 4+
- Provider
Callback Audio, LLC
- Callback Audio, LLC has identified itself as a trader for this app and confirmed that this product or service complies with European Union law.
- DUNS Number
145025264 - Address
20 Gardner Pl
Apt 98
Oneonta New York 13820-1612
United States - Phone Number
+1 6072428020 - Email
info@callbackaudio.com
- Copyright
- © 2026 Callback Audio
