Comparison

Phase Modulator vs Tonic Synth

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Phase Modulator

This app generates complex audio textures and tones by manipulating the phase of a carrier oscillator with a modulating signal. It offers two distinct modes: internal oscillator-to-oscillator modulation or using your audio input as the modulation source. Explore a wide range of sonic possibilities from shimmering harmonics to dense, inharmonic spectra.

Highlights
  • Phase modulation synthesis
  • Internal carrier and modulator oscillators
  • Audio input as modulation source
  • Adjustable carrier and modulator frequencies
  • Modulation index control
  • Selectable oscillator waveforms
  • Amplitude tracking of input audio
Features
Read full description

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.

About

Tonic Synth

A powerful synthesizer app offering three oscillators with diverse sound sources, including physical modeling and wavetables. It features eight analog filter simulations, extensive modulation options, and a full effects rack. Available as a standalone app or AU/AUv3 plugin for Mac and iOS.

Highlights
  • Three oscillators with physical modeling, virtual-analog, wavetable, SF2, and sysex FM
  • Eight analog filter simulations (LP/HP/BP/Notch, 12/24 dB)
  • Comprehensive modulation: LFO, envelope follower, note-per-note filter envelope
  • Full effects rack: chorus, delay, reverb, EQ, compressor, flanger, phaser
  • Standalone app and AU/AUv3 plugin support
  • Live performance features: editable presets, six scenes, MIDI Learn
Features
Read full description

Eight sound engines in one instrument — and a whole preset community living inside it. Physical modeling, virtual analog, 3D wavetable, 6-operator FM and a full SoundFont player: stack up to three engines per sound, each with its own filter, envelope and modulation. Play it standalone on iPhone, iPad and Mac, or load it as an AUv3 plug-in — instrument and effect — in your favorite host. One purchase. No subscription, no ads, nothing locked behind a paywall. • TONICA — THE SOUND COMMUNITY Your next signature sound might come from a player on the other side of the world. Browse what the community publishes without ever leaving the app: one tap auditions it under your fingers, two taps keep it. Love an author? Take their whole collection at once, into a bank named after them. And publish yours with a single tap — no account, no sign-up, no cost. • THREE OSCILLATORS Up to three independent layers — each with its own source, filter, envelope and modulation, plus mute/solo and keyboard split. From a simple patch to a fat, detuned stack on one spread knob. The Vector pad morphs across all three layers in real time: draw a path and the sound travels it on its own. • SOUND ENGINES Per layer: physical modeling (string, modal, wind, bowed), virtual analog (sine, saw, square, triangle, pulse and super-saw, with sub-oscillator and noise), wavetables up to 128 frames, SoundFont (.sf2 and compressed .sf3) and 6-operator FM that opens .syx cartridges. Record anything through the mic and turn it into a wavetable — or draw the waveform with your finger and hear it instantly, on a 3D landscape you can drag, rotate and resize. • FILTERS Eight analog-modeled voicings — LP/HP/BP/Notch, 12 or 24 dB per octave, resonance into self-oscillation, drive and 4× oversampling. From warm ladder to creamy SVF, from acid squelch to screaming resonance. • ARPEGGIATOR & SEQUENCER A step editor with a live playhead: ties, ratchets, accents and per-step probability, polymetric rhythm masks, capture of what you just played, swing, gate mode, key range and per-layer arping. Imports .mid patterns, follows MIDI Clock, and with Hold the pattern runs by itself. • EFFECTS RACK Chorus, tempo-synced ping-pong delay, 6-type FDN reverb, 5-band EQ, compressor and a Flanger/Phaser module — each one switchable and routable per layer. • BUILT FOR THE STAGE Six scenes (A–F) swap the entire patch live without cutting the sound: the note ringing out finishes naturally while the next one already speaks with the new tone. Switched apps mid-set? A sustain pedal left down or a mod wheel parked halfway no longer hijacks your sound — every control starts working again the moment you move it. The MIDI filter decides what each pedal, wheel or controller is allowed to do, and can target one specific device when there's more than one keyboard in the rack. Program Change and Bank Select switch sounds from your controller. MIDI Learn on any control, over USB or Bluetooth. • YOUR LIBRARY 280+ factory sounds in banks, and your own collection beside them: favorites, renaming, saving, tagging and search by name, tag or bank. Two file formats of its own — one to share sounds (.tpr) and one for a full library backup (.tbk). Double-click a file, or receive one by AirDrop, and it merges straight in without duplicating anything. • WHERE IT RUNS iPhone, iPad and Mac, from a single purchase. As an AUv3 it runs in the major recording apps on iOS and macOS. Using software that doesn't load AUv3 yet? See rsjb.com.br/support for the route other users have already proven. Thank you for playing with RSJB - made by musicians for musicians! Follow the news at www.rsjb.com.br/en

Screenshots

Phase Modulator4 screens
Tonic Synth4 screens

Verdict

The call

The clearest difference is price: Phase Modulator at $1.99 against Tonic Synth's $24.99. On rating, ratings volume, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Phase Modulator costs $1.99 and Tonic Synth $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Phase Modulator against 5.0 for Tonic Synth. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Scorecard1 real difference · 9 level
Phase Modulator versus Tonic Synth: the parameters behind the verdict, then further details
ParameterPhase ModulatorTonic Synth
Price$1.99 — better$24.99
Rating5.0 (2 ratings)5.0 (1 ratings)
Positive reviews—100.0% of reviews
Number of ratings2 — better1
Update frequency—Every 4 days
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPadiPhone, iPad, Mac — better
Requires iOS17.017.0
Further details — not scored
Size8 MB34 MB
Age rating4+4+
DeveloperCallback Audio, LLCRubens Felicio

Customer experience

Phase Modulator

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Tonic Synth

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Phase Modulator

No in-app purchases

None

Tonic Synth

No in-app purchases

Questions

Is Phase Modulator free?
Phase Modulator costs $1.99, with no in-app purchases.
Is Tonic Synth free?
Tonic Synth costs $24.99, with no in-app purchases.
Which has better reviews, Phase Modulator or Tonic Synth?
Phase Modulator and Tonic Synth are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.
Do Phase Modulator or Tonic Synth have ads?
Neither Phase Modulator nor Tonic Synth shows ads.

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