Melthaven vs Retromulator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Melthaven
This app provides a note-triggered phase shifter for guitarists, bassists, and synthesizers. It offers organic, rhythmic movement that syncs to your playing, with analog-modeled filters for diverse sonic textures. Enhance loops or create experimental sounds with its input-dependent modulation.
- Note-triggered phase shifting
- Analog-modeled OTA filters
- Responds to guitar and bass transients
- Enhances pre-recorded loops
- Input-dependent synth modulation
- Low-latency engine
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Melthaven is a note-triggered phase shifter built to give guitarists and bassists organic, rhythmic movement that syncs to their playing, rather than a fixed LFO. It's also highly suited for a number of synth basses and sounds with sharp attacks and fast decays. Its analog-modeled OTA filters provide deep resonance and character, ranging from wah-like effects to complex, shifting formant textures or even experimental tones, like bubbling or hard, slappy effects. For bright, harmonically dense signals – such as saturated or overdriven tones and synthetic sounds – the effect range also includes growls and glistening sweeps. FOCUSED ON BASS & GUITARS The effect was specially developed to respond to the frequency response and transient peaks of electric guitars and basses. Every pluck, pop, or pick attack re-triggers the phase sweep, effectively turning your rhythmic timing into the "engine" of the effect. USING LOOPS? BREAK THEM OPEN Add various resonant effects like growls, or vintage bark / quacks "after the fact." This unlocks a level of control usually lost the moment a loop is bounced. Instead of being stuck with locked-in sound design, you can now reshape the envelope of any pre-recorded sample, breathing new life into your loop library. FOR SYNTHS & SOUND DESIGN: INPUT DEPENDENT Soft signals like pads or heavy/layered effects can produce wild, unpredictable responses. While such use is outside the plugin's core design, the smoothing feature can tame these re-triggers, yielding a flow that can feel organic and physical in its instability when operating beyond the plugin’s transient-focused comfort zone. MOVING BEYOND ENVELOPE FILTERS The plugin uses low-latency note detection paired with its own envelope generator and LFO, allowing sculpting and even reshaping each note’s modulation profile or filter envelope. It even detects notes that hide under a consistent signal amplitude when using a traditional envelope follower. BASE FEATURES: - Built around a versatile preset from the Pro version to suit a wide variety of applications - Controls: feedback & panoramic position, attack & hold timings, LFO Rate - Smoothing: from envelope shaping to creating a weighted, fluid response, giving note sequences a sense of physical momentum - Low-latency engine: preserves natural playing feel when used as a real-time effect PRO FEATURES - Requires Pro Edition Upgrade (In‑App Purchase): - Additional envelope parameters, several envelope flavors with pre-mapped control subsets - Pro presets encompassing both strong and milder effects, including the quintessential rubber bass - Enhanced stereo phaser modes & internal stereo re-imaging modulator (for formant-like effects and more) - Vintage-style phaser feedback that can optionally build or ramp with each note onset (non-rampable in the base version) - Instant visual feedback via an audio scope with dual-channel envelopes overlaid on the input waveform TECHNICAL NOTES: - Place before creative effects (unless experimenting). It can be used before or after harmonic processing (saturation, amp sims) depending on your preference - Response may vary on sustained notes with shifting harmonic content - Not optimized for upright bass due to its reliance on sharp signal transients - Note detection involves statistical signal processing and confidence intervals. Weak transients and phantom notes could lead to a loss of output determinism, i.e. sensitivity to changes in certain project settings - While it offers multiple layers of real-time control, Melthaven operates primarily as an automatic effect; for full manual filter manipulation, please refer to RealPhase, a separate app PLEASE NOTE: • The Pro Edition Upgrade is offered as a one‑time In‑App Purchase • An AUv3-compatible host is required to use this app • Suported sampling rates: 44.1, 48, 96 kHz
Retromulator
This app recreates legendary vintage synthesizers, samplers, and keyboards through accurate emulation. It functions as a standalone application or an AUv3 plugin, offering classic electronic music hardware sounds on iOS devices.
- Cycle-accurate hardware emulation
- AUv3 plugin support
- Standalone app functionality
- Full MIDI control
- ROM firmware loading
- Background audio support
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Retromulator is a multi-core retro hardware emulation app and AUv3 plug-in that brings legendary synthesizer, sampler, and keyboard cores back to life through authentic low-level emulation. Each core runs its actual firmware, physical model, or sample data — delivering the unmistakable character of the hardware that defined electronic music from the early 80s through the 2000s. Version 1.6 adds the 88emu core, covering the Roland SC-88, SC-88VL, SC-88Pro, SC-8850 and SC-55mkII GS sound modules with their own Standard MIDI File player. — EMULATED CORES — VIRTUAL ANALOG SYNTHS Motorola DSP 56300 recreation (requires M1 iPad or iPhone 15 Pro or newer): • Access Virus A, B and C • Access Virus TI / TI2 / Snow • Clavia Nord Lead 2X • Waldorf microQ • Waldorf Microwave XT FM SYNTHESIS • Yamaha DX7 — original chip set emulation, based on VDX7 by Charles Chiaccona • Yamaha OPL3 — Nuked OPL3 cycle-accurate FM by Nuke.YKT GM / GS SOUND MODULES • 88emu — Roland SC-88, SC-88VL, SC-88Pro, SC-8850 and SC-55mkII boards, emulation by Giulio Zausa, with GS variation, map and rhythm handling, program and drum kit names read straight from the board ROM, 16-part multitimbral operation, and a Standard MIDI File player with offline rendering to WAV or AAC. CHIPTUNE • Commodore 64 SID 6581/8580 — based on reSID. 3-voice polyphony, 8580 chip model with high-quality RESAMPLE, GoatTracker .sng / .ins bank loading (GTS3/4/5, GTI3/4/5) and .sid file import (PSID/RSID), full macro playback engine (wavetable, pulsetable, filtertable, speedtable) and live MIDI control of cutoff (CC 74), resonance (CC 71), pulse width (CC 75), vibrato (CC 1) and pitch bend. • Ayumi (AY-3-8910 / YM2149) — the PSG behind the ZX Spectrum, Amstrad CPC, Atari ST and MSX. Ayumi emulation by Peter Sovietov with the Ym2149Synth voice engine, 3-voice polyphony, switchable AY / YM engine, .ay patch loading, Factory and User banks, and 11 live CC controls. ELECTRIC PIANO AND SAMPLER • Wurlitzer 200A — OpenWurli physical modelling by hal0zer0 (Rust ported to C++ by discoDSP) • Akai S1000 — SFZero sample engine by Steve Folta, with Bliss Sampler support and resampling engine by discoDSP (SF2 / SFZ / ZBP / ZBB) — KEY FEATURES — • Native AUv3 plug-in for AUM, Cubasis, GarageBand, Logic Pro and more • Standalone app for iPhone and iPad • Full MIDI control: CC, mod wheel, expression, pitch bend • 8-point sinc interpolation for sample playback • Auto-slice drum mapping and global retuning via MIDI • ROM firmware loading from original hardware • Background audio, iCloud and Files app integration • Optimised interpreter compatible with the iOS App Store sandbox
Screenshots
Verdict
The clearest difference is in-app purchases: Retromulator at none against Melthaven's 1. Retromulator also leads on update cadence (every 3 days vs every 6 weeks) and iOS requirement (15.0 vs 17.0). Melthaven's advantage is price ($2.99 vs $9.99). On ads and device support 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
Melthaven costs $2.99 and Retromulator $9.99 up front. Melthaven sells 1 one-off in-app purchase. Retromulator asks for nothing beyond the download.
Melthaven ships an update every 6 weeks, Retromulator every 3 days. The most recent releases landed on September 15, 2026 and September 20, 2026 respectively.
| Parameter | Melthaven | Retromulator |
|---|---|---|
| Price | $2.99 — better | $9.99 |
| Rating | 5.0 (4 ratings) — better | — |
| Positive reviews | — | 50.0% of reviews |
| Number of ratings | 4 — better | — |
| Update frequency | Every 6 weeks | Every 3 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 23 MB | 67 MB |
| Age rating | 4+ | 4+ |
| Developer | quantovox | DiscoDSP LLC |
Customer experience
Melthaven
Retromulator
In-app purchases
Melthaven
- Melthaven Pro$4.99
Retromulator
No in-app purchases









