Phase Modulator vs Harmonitron

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. ------ 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. ----- 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. ------ 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.

Harmonitron is a harmonic tremolo. The rich, swirling amp "vibrato" made famous by early-1960s brownface amplifiers. A normal tremolo just pulses your volume up and down. A harmonic tremolo goes deeper: it splits your sound into a low band and a high band, then sweeps them in OPPOSITE phase. As the lows swell, the highs dip and back again. That contrary motion is what gives Harmonitron its lush, watery, almost phaser-like character that an ordinary tremolo can't reach. Turn the Voice control and the effect morphs smoothly from a classic in-phase tremolo all the way to a full harmonic swirl. Drop it on guitars, keys, synths, pads, drums, or a whole mix. Standalone, or as an Audio Unit (AUv3) effect inside GarageBand, AUM, Logic, and other hosts. THE SOUND • True harmonic tremolo: anti-phase modulation of a low and high band • Voice: morph continuously from classic tremolo to full harmonic swirl • Split & Tilt: place the crossover and balance the two bands • Tube Drive and tone shaping for warmth and grit MOVEMENT • Rate from a slow tide to a fast flutter, shown in BPM • LFO Shape: sine, triangle, square, and ramp with adjustable edge Slope • Tempo Sync that locks to your project and lands on the beat, with musical note divisions from 1/1 to 1/32 (dotted and triplet) • Stereo Spread for auto-pan and rotary-style width HANDS-ON • A living hero orb whose two halves breathe in opposite phase — drag it to set Depth, tap to bypass • Grouped, color-coded controls: Motion, Sync, Harmonic, Stereo, Drive, Output • Factory presets: Brownface, Rotary Swirl, Slow Tide, Sync Chop, Wide Harmonic and more — plus your own saved presets PLUGIN & STANDALONE • Full AUv3 audio-effect support with host presets and parameter automation • Runs on iPhone, iPad, and Mac • Standalone mode with a built-in demo pad, live microphone input, or import a song and export the processed result